ULTRASONIC GRAIN REFINING AND DEGASSINGPROCEDURES AND SYSTEMS

FOR METAL CASTrNG.

BACKGROUND

CROSS-REFERENCE TO RELATED APPLICATION

This applicationis relatedto U.S. Serial No. 62/372,592 (the entire contents of which are incorporated herein byreference) filedAugust 9, 2016, entitled ULTRASONIC GRAIN REFINING AND DEGASSING PROCEDURES AND SYSTEMS FORMETAL CASTING. This applicationis relatedto U.S. Serial No. 62/295,333 (the entire contents of which are incorporated herein byreference) filedFebruary 15, 2016, entitled ULTRAS ONICGRAIN REFINING AND DEGASSING FORMETAL CASTING. This application is related to U.S. Serial No. 62/267,507 (the entire contents ofwhich are incorporated herein by reference) filed December 15,2015, entitled ULTRASONIC GRAIN REFINING AND DEGASSING OF MOLTEN METAL. This application is relatedto U.S. Serial No. 62/113,882 (the entire contents ofwhich are incorporated hereirby reference) filedFebruary 9, 2015, entitled

ULTRASONIC GRAIN REFINING. This application isrelated to U.S. Serial No. 62/216,842 (the entire contentsof which are incorporatedherein by reference)filed September 10, 2015, entitled ULTRASONIC GRAIN REFINING ON A CONTINUOUS CASTING BELT.

Field

The present invention isrelated to a method forproducing metal castingswith controlled grain size, a system for producingthe metal castings, and products obtainedby the metal castings.

Description of the Related Art

Considerable effort hasbeen expendedin the metallurgical field to developtechniques for casting molten metal into continuous metal rod orcast products. Both batch castingand continuous castingsare well developed. There are a number of advantages of continuous casting over batch castings although both are prominently usedin the industry.

In the continuous production oimetal cast, moltenmetal passesfrom a holding furnace into a series of launders and into the mold of a casting wheel where it ieast into a metal bar. The solidified metalbar is removedfrom the casting wheel anddirectedinto a rollingmill where it is rolled into continuousrod. Dependingupon the intended end useof the metal rod product and alloy, the rod maybe subjectedto cooling duringrolling or therod may be cooled or quenched immediatelyupon exitingfrom the rolling mill to impartthereto thedesired mechanical and physicalproperties. Techniques suchas those described in U. S. Pat. No.

3,395,560 to Cofer et al. (the entire contents ofwhich are incorporated herein by reference) have been used to continuously-process a metal rod or bar product.

U.S. Pat. No. 3,938,991 to Sperry et al. (the entire contents ofwhich are incorporated herein by reference) shows that there has beena long recognized problemwith casting of "pure" metal products. By"pure" metal castings, this termrefersto a metal ora metal alloy formed of the primary metallic elements designed fora particular conductivity or tensilestrength or ductility without inclusion of separate impurities addedfor thepurpose ofgrain control.

Grain refiningis a processby whichthe crystal size of the newly formed phase is reduced by either chemical or physical/mechanicalmeans. Grain refiners are usually added into molten metal to significantly reduce the grain size ofthe solidified structure duringthe solidification process or the liquid to solid phase transition process.

Indeed, aWTPO Patent Application WO/2003/033750 to Boily et al. (the entire contents of which are incorporated hereinby reference) describesthe specific useof "grain refiners." The '750 application describes in their background section that,in the aluminum industry, different grain refiners are generally incorporated in the aluminumto form a master alloy. A typical master alloys for use in aluminum casting comprise from 1 tol0% titanium and from 0.1 to 5% boron or carbon, the balance consistingessentially ofaluminum or magnesium, with particles of TiB ₂ or TiC being dispersedthroughout the matrixof aluminum. According to the' 750 application, master alloys containing titaniumand boron can be producedby dissolvingthe required quantities of titanium and boron in an aluminum melt. This isachieved by reacting molten aluminum with KBF ₄ and K ₂ TiF ₆ at temperatures in excess ofiOO °C. Thesecomplex halide salts react quickly with molten aluminum and provide titanium andboron to themelt.

The '750 application also describesthat, as of 2002, this technique wasused to produce commercial master alloys by almost all grain refiner manufacturingcompanies. Grain refiners frequently referred to as nucleating agentsare still usedtoday. For example, one commercial supplier of a TIBOR master alloy describesthat the closecontrol of the cast structureis a maj or requirement inthe production of high quality aluminum alloy products. Prior to this invention, grain refiners wererecognizedas the most effectiveway to provide a fine and uniform as-cast grain structure. The followingreferences (all the contentsaf which are incorporated herein by reference) provide details ofthis background work:

Abramov, O. V., (1998), "High-Intensity Ultrasonics, " Gordon and Breach Science Publishers, Amsterdam, The Netherlands, pp. 523-552.

Alcoa, (2000), "New Process for Grain Refinement of Aluminum, " DOE Project Final Report, Contract No. DE-FC07-98ID 13665, September 22, 2000.

Cui, Y., Xu, C.L. and Han, Q., (2007), "Microstructure Improvement in Weld Metal Using Ultrasonic Vibrations, Advanced Engineering Materials, " v. 9, No. 3, pp.161-163.

Eskin, G.I., (1998), "Ultrasonic Treatment of Light Alloy Melts, " Gordon and Breach Science Publishers, Amsterdam, The Netherlands.

Eskin, G.I. (2002) "Effect of Ultrasonic Cavitation Treatment of the Melt on the Microstructure Evolution during Solidification of Aluminum Alloy Ingots, " Zeitschrifi Fur Metallkunde/Materials Research and Advanced Techniques, v.93, n.6, June, 2002, pp. 502-507.

Greer, A.L., (2004), "Grain Refinement of Aluminum Alloys, " in Chu, M.G., Granger, D.A., and Han, Q., (eds.), " Solidification of Aluminum Alloys, " Proceedings of a Symposium Sponsored by IMS (The Minerals, Metals & Materials Society), IMS, Warrendale, PA 15086-7528, pp. 131-145.

Han, Q., (2007), The Use of Power Ultrasound for Material Processing, " Han, Q., Ludtka, G., and Zhai, Q., (eds), (2007), "Materials Processing under the Influence of External Fields, " Proceedings of a Symposium Sponsored by TMS (The Minerals, Metals & Materials Society), TMS, Warrendale, PA 15086- 7528, pp. 97-106.

Jackson, K.A., Hunt, J.D., and Uhlmann, D.R., and Seward, TP., (1966), "On Origin of Equiaxed Zone in Castings, " Trans. Metall. Soc. AIME, v. 236, pp.149-158.

Jian, X, Xu, H, Meek, T. T., and Han, Q., (2005), "Effect of Power Ultrasound on Solidification of Aluminum A356 Alloy, " Materials Letters, v. 59, no. 2-3, pp. 190-193.

Keles, O. and Dundar, M., (2007). "Aluminum Foil: Its Typical Quality Problems and Their Causes, " Journal of Materials Processing Technology, v. 186, pp.125- 137.

Liu, C, Pan, Y., and Aoyama, S., (1998), Proceedings of the 5 ^th International Conference on Semi-Solid Processing of Alloys and Composites, Eds.: Bhasin, A.K., Moore, J.J., Young, K.P., and Madison, S., Colorado School of Mines, Golden, CO, pp. 439-447.

Meg , J., (1999), "Molten Metal Treatment, " US Patent No. 5,935,295, August, 1999

Megy, J, Granger, D.A., Sigworth, G.K., and Durst, C.R., (2000), "Effectiveness of In-Situ Aluminum Grain Refining Process, " Light Metals, pp.1-6.

Cui et al., "Microstructure Improvement in Weld Metal Using Ultrasonic

Vibrations, " Advanced Engineering Materials, 2007, vol. 9, no. 3, pp. 161- 163. Han et ah, "Grain Refining of Pure Aluminum, " Light Metals 2012, pp. 967-

971.

Prior to this invention, U. S. Pat. Nos. 8,574,336 and 8,652,397 (the entire contentsof each patent are incorporated herein by reference) described methods for reducing the amountof a dissolvedgas (and/orvarious impurities) ina molten metal bath (e.g., ultrasonic degassing)for example by introducing a purginggas into the moltenmetal bath in close proximity to the ultrasonic device. These patents will bereferred tohereinafter as the'336 patent and the '397 patent.

SUMMARY In one embodiment ofthe present invention, there isprovided a molten metal processing device foiattachment toa casting wheelon a casting mill. The device includes an assembly mounted on the casting wheelnicluding atleast one vibrational energy source which supplies vibrational energy tcmolten metal cast in the casting wheel while the moltemnetal in the casting wheelis cooled and includes a support device holding thevibrational energy source.

In one embodiment ofihe presentinvention, thereis provided a method for formingi metal product. The method provides molten metal intoa containment structure included as a part of a casting mill. The methodcools the molten metalin the containment structure,and couples vibrational energy intothe molten metal inthe containment structure.

In one embodiment ofthe presentinvention, thereis provided a system for formingi metal product. The system includesl) the moltenmetal processing device describedtbove and 2) a controllerincluding data inputs and control outputs, and programmed with control algorithms whichpermit operation of the above-described method steps. In one embodiment ofthe presentinvention, thereis provided a molten metalprocessing device. The device includes a source of molten metal, an ultrasonicdegasser including an ultrasonic probe inserted intothe molten metal, a casting for reception of the moltermetal, an assembly mounted on the casting,including at leastone vibrational energysource whichsupplies vibrational energyto molten metal cast in the casting while the molten metal in the castingis cooled, and a support deviceholding the at leastone vibrational energy source.

It is to be understoodthat both the foregoing general description of the invention arttte following detailed descripti on are exemplary, but are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

A more completeappreciation of the invention andnany of the attendantadvantages thereof will be readily obtained as the same becomesbetter understood by referenceto the following detailed descripti on when consideredin connection with the accompanying drawings, wherein:

Figure 1 is a schematic ofa continuous casting mill accordingto one embodiment of the invention;

Figure 2 is a schematic ofa casting wheel configurationaccording to one embodiment of the invention utilizing at least one ultrasonic vibrational energy source;

Figure 3 is a schematic ofa casting wheel configurationaccording to one embodiment of the invention specificallyutilizing at least one mechanically-driven vibrationabnergy source;

Figure 3 A is a schematic ofa casting wheelhybrid configurationaccordingto one embodiment ofthe invention utilizingboth at least one ultrasonicvibrational energysource and at least one mechanically-driven vibrational energyiource;

Figure 4 is a schematic ofa casting wheel configurationaccording to one embodiment of the inventionshowinga vibrational probe devicecoupled directly to themolten metal cast in the casting wheel;

Figure 5 is a schematic ofa stationary mold utilizing thevibrational energysources of the invention;

Figure 6A is a cross sectional schematic of selected componentsf a vertical casting mill; Figure 6B is a cross sectional schematicof other components of a verticabasting mill;

Figure 6C is a cross sectional schematicof other components of a verticabasting mill; Figure 6D is a cross sectional schematic of other components of a verticaiasting mill; Figure 7 is a schematic ofan illustrative computer system for thecontrolsand controllers depicted herein;

Figure 8 is a flowchart depicting a methodaccording to one embodimentif the invention;

Figure 9 is a schematic depicting anembodiment ofthe invention utilizing both ultrasonic degassing andultrasonic grain refinement;

Figure 10 is an ACSR wire processflow diagram;

Figure 11 is an ACSS wire process flowdiagram;

Figure 12 is an aluminum strip process flowdiagram;

Figure 13 is a schematic side view of a casting wheel configuration accordirlg one embodiment ofthe invention utilizingfor the at least one ultrasonic vibrational energysource a magnetostrictive element;

Figure 14 is a sectional schematicof the magnetostrictive elemenof Figure 13;

Figure 15 is a micrographiccomparison of analuminum 1350 EC alloy showing the grain structure of castings with no chemical grain refiners, withgrain refiners, andwith only ultrasonic grain refining;

Figure 16 is tabular comparison of a conventionall350 EC aluminum alloy rod(with chemical grain refiners)to a 1350 EC aluminum alloy rod (with ultrasonic grain refinement);

Figure 17 is tabular comparison of a conventionalACSR aluminum Wire 0.130" Diameter (with chemical grain refiners)to ACSR aluminum Wire 0.130" Diameter (with ultrasonic grain refinement);

Figure 18 is tabular comparison of a conventionale 176 EEE aluminum alloy rod (with chemical grain refiners)to an 8176 EEE aluminum alloy rod (with ultrasonic grain refinement);

Figure 19 is tabular comparison of a conventional? 154 aluminum alloy rod (with chemical grain refiners)to a 5154 aluminum alloy rod (with ultrasonic grain refinement);

Figure 20 is tabular comparison of a conventional 154 aluminum alloy strip (with chemical grain refiners)to a 5154 aluminum alloy strip(with ultrasonic grain refinement); and

Figure 21 is tabular depiction of the properties of a 5356 aluminumalloy rod (with ultrasonic grain refinement).

.

DETAILED DESCRIPTION

Grain refining of metals and alloys is important for manyreasons, including maximizing ingot castingrate, improving resistanceto hot tearing, minimizing elemental segregation, enhancing mechanical propertiesparticularly ductility, improving thefinishingcharacteristicsof wrought products andincreasing the mold filling characteristics, andecreasing theporosity of foundry alloys. Usually grainrefining is one ofthe first processing steps for theproduction of metal and alloy products, especially aluminum alloysand magnesium alloys, which are two of the lightweight materialsused increasingly inthe aerospace, defense, automotiveponstruction, and packaging industry. Grain refinings also an important processing step for making metals and alloys castableby eliminating columnar grainsand forming equiaxed grains.

Grain refining is a solidification processing step by which the crystal size of the solid phases is reduced by either chemical, physical, or mechanical means in order to make alloys castable and to reduce defect formation. Currently, aluminum production is grain refined using TIBOR, resulting in the formation of an equiaxed grain structure in the solidified aluminum.

Prior to this invention,use of impuritiesor chemical "grain refiners" was theonly way to address the long recognized problem in the metal casting industry ofolumnar grain formation in metal castings. Additionally prior to thisinvention, a combination of 1) ultrasonic degassing to remove impurities from the moltenmetal (prior to casting) alongand 2) the above-noted ultrasonic grain refining (i.e., atleast one vibrational energy source)had notbeen undertaken. However, there are large costs associated with using TIBOR and mechanical restraints due to the input of those inoculants into the melt. Some of the restraints include ductility, machinability, and electrical conductivity.

Despite the cost, approximately68% ofthe aluminum producedin the UnitedStates is first cast into ingot prior tofurther processinginto sheets, plates, extrusions, or foil. The direct chill (DC) semi-continuous casting proces&nd continuous casting(CC) processhas been the mainstay of thealuminum industry duelargely to its robust nature andrelative simplicity. One issue with the DC and CC processes is the hot tearingformationor cracking formation during ingot solidification. Basically, almost allngots would be cracked(or not castable) without using grain refining.

Still, the production rates of these modern processesare limited by the conditionsto avoid cracking formation. Grain refiningis an effective way to reduce thdiot tearing tendency of an alloy, and thus to increase the production rates. As a result^ significant amount of effort has been concentratedon the developmentof powerful grainrefinersthat can producegrain sizes as small as possible. Superplasticity can beachievedif the grain size can be reduced to thesub- micron level, which permitsalloys not onlyto be castat much faster ratesbut also

rolled/extrudedat lower temperatures at much faster ratesthan ingots are processed today, leading to significantcost savingsand energy savings. At present, nearly all aluminumcast in the worldeither from primary(approximately 20 billion kg) or secondaryand internal scrap (25 billionkg) is grain refined with heterogeneous nuclei of insoluble Ti¾ nuclei approximately a few microns in diameteiwhich nucleate a fine grain structure inaluminum. One issue relatedto the use ofchemical grain refinersis the limited grain refining capability. Indeedfhe use of chemical grain refiners causes a limited decreasen aluminum grain size, from a columnar structure withlinear grain dimensionsof something over 2,500 μπι, to equiaxedgrains of less than200 μπι. Equiaxed grains of ΙΟΟμπι in aluminum alloys appear to be the limitthat can be obtained using the chemical grain refiners commercially available.

The productivity can besignificantly increased if the grain sizecan be further reduced.

Grain size in the sub-micron levelleads to superplasticity that makes formingof aluminum alloys much easier atroom temperatures.

Another issue related tothe use of chemical grain refiners is thedefect formation associated with the use of grain refiners. Although considered in the prior artto be necessary for grain refining, the insoluble, foreign particlesare otherwise undesirablein aluminum, particularly in the form ofparticle agglomerates ("clusters"). Thesurrent grain refiners,which are presentin the form of compoundsin aluminum base master alloys, are producecby a complicated string ofinining, beneficiation,and manufacturing processes. Themaster alloys used now frequently contain potassium aluminunfluoride (KAIF)salt and aluminum oxide impurities (dross) which arisefrom the conventional manufacturingprocess of aluminum grain refiners. These give rise to local defectsin aluminum (e.g. "leakers" in beverage cans and "pin holes" inthin foil), machine tool abrasion, and surface finish problems in aluminumData from one of the aluminum cable companies indicate that25% of the production defects- s due to TiB ₂ particle agglomerates,and another 25% of defectsis due to dross thatis entrapped into aluminum during the casting process. Ti¾ particle agglomeratesoften break the wires during extrusion, especially whenthe diameter of the wires is smalleithan 8 mm.

Another issue related tothe use of chemical grain refiners is thecost of the grain refiners. This is extremelytrue for the productionof magnesium ingotsusing Zr grain refiners. Grain refining using Zrgrain refiners costs about arextra $ 1 per kilogram of Mg castingproduced. Grain refinersfor aluminum alloys costaround $ 1.50 per kilogram.

Another issue related tothe use of chemical grain refiners is thereduced electrical conductivity. The useof chemical grain refiners introduces in excess amount of Th aluminum, causes a substantial decrease irielectrical conductivity of pure aluminum foicable applications. In order to maintain certain conductivity,companies ave to pay extra moneyto use purer aluminum for making cables and wires.

A number of other grain refining methods, in additioto the chemical methods, have been explored in thepast century. These methodsinclude using physical fields,such as magnetic and electro-magneticfields, and using mechanical vibrations. High-intensity, low-amplitude ultrasonic vibration isone of the physical/mechanical mechanisms thdtas been demonstrated for grain refmingof metals and alloys without using foreignparticles. However, experimental results, suchas from Cui et al, 2007 noted above, were obtained in small ingots up tea few pounds ofmetal subjected to a shortperiod oftime ofultrasonic vibration. Littleefforthas been carried out on grain refmingof CC orDC casting ingots/billets using high-intensityiltrasonic vibrations.

Some of the technical challenges addressedn the present invention fograin refiningare (1) the coupling of ultrasonic energyto the molten metal for extended times, (2) maintaining the natural vibration frequencies ofthe system at elevated temperatures, and(3) increasing thegrain refining efficiencyof ultrasonic grain refining when the temperature ofhe ultrasonic wave guide is hot. Enhanced cooling for boththe ultrasonic wave guideand the ingot (as described below) is one of the solutions presentedhere for addressingthese challenges.

Moreover, another technical challenge addressed in thpresent invention relates to the fact that, thepurer the aluminum, the harder it is toobtain equiaxed grains duringthe solidification process. Even with the use ofexternal grain refiners suchas TiB (Titanium boride) in pure aluminum such as 1000, 1100 and 1300 series of aluminum, it remains difficultto obtain an equiaxedgrain structure. However, using the novel grain refining technology described herein,substantial grain refining has beerobtained.

In one embodiment ofthe invention, the present inventioipartially suppresses columnar grain formation withoutthe necessity of introducing grain refiners. The application of vibrational energy tothe molten metal as it isbeing poured intoa casting permits the realization of grain sizes comparable toor smaller than that obtained with stateof the art grain refiners such as TIBOR master alloy.

As used herein,embodiments ofthe present invention will be describedising

terminologies commonlyemployedby those skilledin the art to present their work. These terms are to be accordedthe common meaning asunder stood by those of the ordinary skill inthe arts of materials science, metallurgy ,metal casting, and metal processing. Some terms taking a more specialized meaning aredescribedin the embodiments below. Nevertheless, the term

"configured to" isunderstood herein to depictappropriate structures (illustratedherein or known or implicit from the art)permitting an object thereof to performthe function which follows the "configured to" term. The terrri'coupled to" meansthat one object coupled to a second obj ect has the necessary structures to support the first obj ectn a positionrelative to the second obj ect (for example, abutting, attached, displaced a predetermined distance from, adjacent ontiguous, j oined together, detachablefrom one another,dismountable fromeach other, fixed together, in sliding contact,in rolling contact) with or without direct attachment of the first andecond objects together.

U. S. Pat. No. 4,066,475 to Chia et al. (the entire contents of which are incorporated herein by reference) describes a continuous casting process. In general, Figure 1 depicts continuous casting system having a casting mill 2 includinga pouring spout 1 1 which directs the molten metal to a peripheral groove contained ona rotary mold ring 13. An endlessflexible metal band 14 encircles botha portion of the mold ring 13as well as a portionof a set of band- positioning rollersl 5 such that a continuous casting mold is definecby the groove inthe mold ring 13 and the overlying metalband 14. A cooling system is provided r cooling the apparatus and effecting controlled solidificatioKDf the moltenmetal during its transport on the rotary mold ring 13. The cooling system includes a plurality of sideheaders 17, 18, and 19 disposed on the side of the mold ring 13 and inner and outer band headers 20and 21 , respectively,disposed on the inner and outer sides ofthe metal band 14 at a location where it encircles the moldring. A conduit network 24 having suitable valving is connected to supply ancexhaust coolant to the various headers so as to control the cooling of the apparatus and the rate of solidification of the molten metal.

By such a construction, molten metals fed from the pouring spout 1 1 into the casting mold and is solidified andpartially cooled during its transport by circulation of coolant through the cooling system. A solidcast bar 25 is withdrawn from the castingwheel and fed to a conveyor 27 whichconveysthe cast bar to a rollingmill 28. It should be noted thatthe cast bar 25 has only been cooled an amountsufficientto solidify the bar, and the bar remains atan elevated temperatureto allow an immediate rolling operation to be performed thereon.The rolling mill 28 can include a tandem array ofrolling stands which successively rollhe bar into a continuous length of wire rod30 which has a substantially uniform,circular cross-section.

Figures 1 and 2 show controller500 which controls thevarious parts ofthe continuous casting system showntherein, as discussed inmore detail below. Controller500 may include one or more processorswith programmed instructions (i.e., algorithms) tocontrol the operation of the continuously casting system and the components thereof. In one embodiment ofthe invention, as shownin Figure 2, castingmill 2 includes a casting wheel 30having a containment structure 32(e.g., a trough or channelin the casting wheel 30) in whichmolten metal is poured (e.g., cast) anda molten metal processingdevice 34. A band 36 (e.g., a steel flexible metalband) confinesthe moltenmetal to the containment structure 32 (i.e., the channel). Rollers 38 allow the molten metalprocessingdevice 34 to remain in a stationary position on the rotating casting wheelas the moltenmetal solidifiesin the channel ofthe casting wheeland is conveyed awayfrom themolten metal processingdevice 34.

In one embodiment ofthe invention, moltenmetal processing device 34 includes an assembly 42 mountedon the casting wheel 30. The assembly 42 includes at least one vibrational energy source(e.g., vibrator40), a housing 44 (i.e., a support device) holding the vibrational energy source42. The assembly 42includes atleast one cooling channel 46 for transport of a cooling medium therethrough. The flexibleband 36 is sealed to thehousing 44 by a seal 44a attached to the undersideof the housing,thereby permitting thecooling medium from the cooling channel to flow alonga side of the flexible band opposite th nolten metalin the channel ofthe casting wheel. Anair wipe 52 directs air (as a safety precaution) such that any water leaking fromthe cooling channelwill be directed alonga direction away fromthe casting source of themolten metal. Seal 44a canbe made froma number of materials including ethylene propylene, viton,buna-n (nitrile),neoprene, siliconerubber, urethane, fluorosilicone, polytetrafluoroethylene as well asather known sealant materials. In one embodiment^ the invention, a guide device (e.g., rollers38) guides the molten metalprocessingdevice 34 with respectto the rotating casting wheeBO. The coolingmedium provides cooling to themolten metal in the containment structure 32 and/or the at leastone vibrational energysource 40. In one embodiment ofthe invention, components of the moltermetal processing device 34 including the housing canbe made froma metal such titanium, stainless steelalloys, low carbon steels or HI 3 steel, other high-temperature materials,a ceramic, a compositeur a polymer Components ofthe molten metal processingdevice 34 can be made fromone or moreof niobium, aniobium alloy, titanium, a titanium alloy, tantalum, a tantalum alloy, copper,a copper alloy, rhenium, a rhenium alloy, steel, molybdenum, a molybdenum alloy, stainlesssteel, and a ceramic. The ceramic can bea silicon nitride ceramic, suchas for example a silica alumina nitride or SIALON.

In one embodiment ofthe invention, as a moltenmetal passes underthe metal band 36 under vibrator 40, vibrational energy is supplied to the molten metal as the metalbegins tocool and solidify. In one embodimentof the invention, the vibrational energyis imparted with ultrasonic transducers generated for example by piezoelectric devicesultrasonic transducer. In one embodiment ofthe invention, the vibrational energy is imparted with ultrasonic transducers generated for exampleby a magnetostrictivetransducer. In oneembodiment ofthe invention, the vibrational energy isimparted with mechanicallydriven vibrators (to be discussed later).The vibrational energy inone embodimentpermits the formation of multiple smalfceeds, thereby producing a fine grain metal product.

In one embodiment ofthe invention, utrasonic grain refining involves application of ultrasonic energy (and/or other vibrational energy) for the refinement of the grain size. While the invention is not bound to any particular theory, one theory is that the injection of vibrational energy (e.g., ultrasonic power) into a molten or solidifying alloy can give rise to nonlinear effects such as cavitation, acoustic streaming, and radiation pressure. These nonlinear effects can be used to nucleate new grains, and break up dendrites during solidification process of an alloy.

Under this theory, the grain refining process can be divided into two stages: 1) nucleation and 2) growth of the newly formed solid from the liquid. Spherical nuclei are formed during the nucleation stage. These nuclei develop into dendrites during the growth stage.

Unidirectional growth of dendrites leads to the formation of columnar grains potentially causing hot tearing/cracking and non-uniform distribution of the secondary phases. This in turn can lead to poor castability. On the other hand, uniform growth of dendrites in all directions (such as possible with the present invention) leads to the formation of equiaxed grains.

Castings/ingots containing small and equiaxed grains have excellent formability.

Under this theory, when the temperature in analloy is below theliquidus temperature; nucleation may occur when the size of the solidembryos is larger than a critical size given in the followin equation:

where r* is the critical size, is the interfacial energy associated with the solid-liquid interface, and ^& _^ j _{s me} Qibbs f _{ree ener} gy associated with the transformation of a unit volume of liquid into solid..

Under this theory, the Gibbs free energy, ^ ^' ^ ^" , decreases with increasing size of the solid embryos when their sizes are larger than r*, indicating the growth of the solid embryo is thermodynamically favorable. Under such conditions, the solid embryos become stable nuclei. However, homogeneous nucleation of solid phase having size greater than r* occurs only under extreme conditions that require large undercooling in the melt. Under this theory, the nuclei formed duringsolidification can growinto solid grains known as dendrites. The dendritescan also bebroken into multiple small fragmentsby application ofthe vibrational energy. The dendritic fragments thus formed cargrow into new grains and result in the formation of small grains; thus creating an equiaxed grain structure.

While notbound to any particular theory, a relatively small amount of undercoolingto the molten metal (e.g., lessthan 2, 5, 10, or 15 °C) at the top of the channel of casting wheel 30 (for example against the undersideof band 36) resultsin a layer of small nuclei of pure aluminum (or other metal or alloy) being formed against the steel band. The vibrational energy (e.g., the ultrasonic or the mechanicallydriven vibrations) releasethese nuclei whichthen are used as nucleating agents duringsolidification resultingin a uniform grain structure.

Accordingly, inone embodimentof the invention, the cooling method employed ensures that a small amount of undercooling at the top of the channelof casting wheel 30 against the steel band results in small nuclei of the material being processed into themolten metal as the moltenmetal continues to cool. The vibrations acting onband 36 serve to disperse these nucleinto the molten metal in the channel of casting wheel 30 and/or can serve to break updendntesthat form in the undercooled layer. For example, vibrational energy imparted into the moltenmetal as it cools can by cavitation (see below)break up dendrites toform newnuclei. Thesenuclei and fragments of dendritescan then be used to form (promote)equiaxed grains in the moldduring solidification resultingin a uniform grain structure.

In other words, ultrasonic vibrations transmitted into theundercooled liquid metal create nucleation sites inthe metals ormetallic alloys torefinethe grain size. Thenucleation sites can be generated via thevibrational energy actingas described above tobreak up the dendrites creating in themolten metal numerous nuclei which are not dependent on foreign impuritiesln one aspect, the channelof the casting wheel30 can be a refractory metal or other high temperature materialsuch as copper, ironsand steels, niobium, niobiumand molybdenum, tantalum, tungsten, and rhenium, andalloys thereof includingone or more elements such as silicon, oxygen, or nitrogen whiclcan extendthe melting pointsof these materials.

In one embodiment ofthe invention, the sourceof ultrasonic vibrations for vibrational energy source 40 provides apower of 1.5 kW at an acoustic frequencyof 20 kHz. This inventionis not restricted to those powers and frequencies. Rather, a broad range of powers and ultrasonic frequenciescan be used although thefollowing ranges are ofinterest.

Power: In general, powers between50 and 5000 W for each sonotrode, dependingon the dimensions of thesonotrode or probe. These powersare typically applied to the sonotrode toensure thatthe power density at the end of thesonotrode ishigherthan 100 W/cm ² , which may be consideredthe thresholdfor causing cavitationin moltenmetals depending on the cooling rate of the molten metal, the molten metaltype, and other factors. The powers atthis area can range from50 to 5000 W, 100 to 3000 W, 500 to 2000 W, 1000 to 1500 W or any intermediate oroverlapping range. Higher powers for larger probe/sonotrodeand lower powers for smaller probeare possible. Invarious embodimentsof the invention, theapplied vibrational energy powedensity can range from 10 W/cm ² to 500 W/cm ² , or 20 W/cm ² to 400 W/cm ² , or 30 W/cm ² to 300 W/cm ² , or 50 W/cm ² to 200 W/cm ² , or 70 W/cm ² to 150 W/cm ² , or any intermediateor overlapping rangesthereof.

Frequency: In general, 5 to400 kHz (or any intermediate range) may be used.

Alternatively, lOand 30 kHz (or any intermediate range) maybe used. Alternatively, 15 and 25 kHz (or any intermediate range)may be used. The frequency applied can range from 5 to 400 KHz, lOto 30 kHz, 15 to 25 kHz, 10 to 200 KHz, or 50 to 100 kHz or any intermediateor overlapping rangesthereof.

In one embodiment ofthe invention, dispose fcoupled to thecooling channels 46 is at least one vibrator 40 which in the case of an ultrasonic waveprobe (or sonotrode,a piezoelectric transducer, orultrasonic radiator, or magnetostrictiveelement) ofan ultrasonictransducer providesultrasonic vibrational energy through the cooling medium asvell as through the assembly 42 and the band 36 into the liquid metal. In one embodimentof the invention, ultrasonic energy is supplied from a transducer that is capable of converting electricaburrents to mechanical energythus creating vibrational frequenciesabove 20 kHz (e.g., up to 400 kHz), with the ultrasonic energy being supplied from either or both piezoelectric elementsor magnetostri cti veel ements .

In one embodimentof the invention, anultrasonic waveprobe is insertedinto cooling channel 46 to be in contact with a liquid cooling medium. In one embodiment of the inventiona separation distance from a tip of the ultrasonic wave probeto the band 36, if any, is variable. The separation distance maybe for example less than 1 mm, lessthan 2 mm, lessthan 5 mm, less than 1 cm, less than 2 cm, less than 5 cm, less than 10 cm, lessthan 20, or lessthan 50 cm. In one embodimentof the invention, more than one ultrasonic waveprobe or an array of ultrasonic wave probes can be insertedinto cooling channel46 to be in contact with a liquid cooling medium. In one embodiment ofthe invention, the ultrasonic wave probe carbe attached to a wall of assembly 42.

In one aspect of the inventionpiezoelectrictransducers supplying thevibrational energy can be formed of a ceramic material that is sandwiched betweerelectrodes whichprovide attachment pointsfor electrical contact. Once a voltageis applied to theceramic throughthe electrodes, theceramic expands and contracts at ultrasonic frequencies. In one embodiment the invention, piezoelectrictransducer serving as vibrationalenergy source 40 is attached to a booster, which transfers the vibration to the probe. U. S.Pat. No. 9,061,928 (the entire contents of which are incorporated hereinby reference) describesan ultrasonic transducer assembly including an ultrasonic transducer, anultrasonic booster, anultrasonic probe, and a booster coolingunit. The ultrasonic booster in the '928 patent is connected to theultrasonic transducer to amplify acoustic energy generated bythe ultrasonic transducer andtransfer the amplified acoustic energy to the ultrasonic probe. The booster configurationof the '928 patent can be useful here in the present invention toprovide energyto the ultrasonic probes directly or indirectly in contact with the liquid coolingmedium discussedabove.

Indeed, in one embodiment ofthe invention, anultrasonic booster is used in the realm of ultrasonics to amplify or intensifythe vibrational energy created by a piezoelectric transducer. The booster does not increase or decreasethe frequency ofthe vibrations, it increases the amplitude of the vibration. (When a booster is installedbackwards, it can also compress the vibrational energy.) In one embodimentof the invention^ booster connects between the piezoelectric transducer andthe probe. In thecase ofusing a booster forultrasonic grain refining, below are an exemplary number of method steps illustrating thaise of a booster with a piezoelectric vibrational energysource:

1) An electrical current issupplied to the piezoelectric transducer The ceramic pieces within the transducer expand and contract once the electrical current is applied, this converts the electrical energy to mechanical energy.

2) Those vibrations in one embodimentare then transferred to a booster, which amplifies or intensifiesthis mechanical vibration.

3) The amplified or intensified vibrationsfrom the boosterin one embodiment are then propagated to the probe. The probe isthen vibrating at theultrasonic frequencies, thus creating cavitations.

4) The cavitations from the vibrating probeimpact the casting band, which in one embodiment isin contact with the molten metal. 5) The cavitations in one embodiment break upthe dendrites and creatingan equiaxed grain structure.

With reference to Figure2, the probe iscoupled to the coolingmedium flowingthrough molten metal processing device34. Cavitations, thatare producedin the coolingmedium via the probe vibrating at ultrasonic frequencies, impact the band36 which is in contactwith the molten aluminum in the containment structure 32.

In one embodiment ofthe invention, the vibrational energy caibe supplied by

magnetostrictivetransducers serving as vibrational energy source 40. In one embodiment^ magnetostrictivetransducer serving as vibrational energy source 40has the same placement that is utilized with the piezoelectrictransducer unit of Figure 2, with the only difference being the ultrasonic source driving the surface vibrating at the ultrasoni (frequency is at least one magnetostrictivetransducer instead of at least one piezoelectric element. Figure! 3 depicts a casting wheel configuration according to one embodiment^ the invention utilizing forthe at least one ultrasonic vibrational energy source a magnetostrictive element40a. In this

embodiment ofthe invention, the magnetostrictivetransducer(s) 40a vibrates a probe(not shown in the side view of Figure 13) coupled to the cooling medium afe frequency for example of 30 kHz, although other frequenciescan be used as describedbelow. Inanother embodimentof the invention, the magnetostrictivetransducer 40a vibrates a bottomplate 40b shown in theFigure 14 sectional schematic insidemolten metal processingdevice 34 with the bottom plate 40bbeing coupled to the cooling medium (shown inFigure 14).

Magnetostrictive transducers are typically composed of a large number of material plates that will expand and contract once an electromagnetic fieldis applied. More specifically, magnetostrictivetransducers suitable for the present inventiorcan include in one embodiment a large number of nickel (or othermagnetostrictivematerial) plates or laminations arranged in parallel with one edge of each laminate attached to the bottom of a process container or other surface to be vibrated. A coilof wire is placed around themagnetostrictive material to provide the magnetic field. For example,when a flowof electrical current is suppliedthrough the coil of wire, a magnetic field is created. This magnetic field causesthe magnetostrictive material to contract or elongate, thereby introducing a soundwave into a fluid in contactwith the expanding and contractingmagnetostrictivematerial. Typical ultrasonic frequencies from magnetostrictive transducers suitablefor the invention rangefrom 20 to 200 kHz. Higher or lower frequencies can be used depending on thenatural frequency of the magnetostrictive element.

For magnetostrictive transducersnickel is one ofthe most commonly used materials. When a voltage is applied to the transducer, the nickel material expands and contractat ultrasonic frequencies. In one embodimentof the invention, the nickel plates are directlysilver brazed to a stainless steel plate. Withreferenceto Figure 2, the stainlesssteel plate of the magnetostrictive transduceris the surface that is vibratingat ultrasonic frequenciesand is the surface (orprobe) coupled directly tothe coolingmedium flowing through molten metal processing device 34. Thecavitations that are produced in thecooling medium via theplate vibrating at ultrasonicsfrequencies,then impact the band 36 which is in contactvith the molten aluminum in the containmentstructure 32.

U.S. Pat. No. 7,462,960 (the entire contentsof whichare incorporated herein by reference) describes an ultrasonic transducer driverhaving a giant magnetostrictiveelement. Accordingly, inone embodimentof the invention, the magnetostrictive elementan be made from rare-earth-alloy -basedmaterials such as Terfenol-D andits compositeswhich have an unusually large magnetostrictiveeffect ascompared with early transitionmetals, such as iron (Fe), cobalt (Co) and nickel (Ni). Alternatively, the magnetostrictiveslementin one embodiment ofthe invention can be made from iron (Fe), cobalt(Co) and nickel (Ni).

Alternatively, the magnetostrictive elemental one embodiment ofthe invention canbe made from one or more of thefollowing alloys iron andterbium; iron and praseodymium; iron, terbium and praseodymium; iron and dysprosium; iron,terbium and dysprosium; iron, praseodymium and dysprodium;iron, terbium, praseodymiumand dysprosium; iron,and erbium; iron and samarium; iron, erbium and samarium; iron, samarium and dysprosium; iron and holmium; iron, samarium and holmium; or mixture thereof.

U.S. Pat. No. 4, 158,368 (the entire contentsof whichare incorporated herein by reference) describes a magnetostrictive transducer. As describetflherein and suitable for the present invention, the magnetostrictive transduceican include a plunger of a material exhibiting negative magnetostrictiondisposed withina housing. U. S. Pat. No.5, 588,466 (the entire contents of which are incorporatedherein by reference) describesa magnetostrictive transducer. As describedtherein and suitable for the present invention^ magnetostrictive layer is appliedo a flexible element, for example, a flexiblebeam. The flexible element is deflectedby an external magnetic field. As describedin the '466 patent and suitablefor the present invention^ thin magnetostrictivelayer can be used for the magnetostrictive element hich consists of Tb(l-x) Dy(x) Fe ₂ . U.S. Pat. No. 4,599,591 (the entire contents of which are incorporated hereirby reference) describes a magnetostrictive transducer. As describedherein and suitable for the present invention, the magnetostrictive transduceican utilize a magnetostrictivematerial and a plurality of windingsconnectedto multiple current sources having a phase relationshipso as to establisha rotating magnetic induction vectorwithin the magnetostrictivematerial. U.S. Pat. No. 4,986808 (the entire contents of which are incorporated herein by reference) describes a magnetostrictive transducer. As described thereinand suitable for the present invention, the magnetostrictive transducercan include a plurality of elongatedstrips of magnetostrictive material, each strip having a proximal end, a distal end andi substantially V-shaped cross section with each arm of the V is formed bya longitudinal length ofthe strip and each strip being attached to an adjacent strip at both the proximal end and the distal endto form andintegral substantially rigid column havinga central axis with fins extending radially relative to this axis.

Figure 3 is a schematic ofanother embodimentof the invention showing a mechanical vibrational configurationfor supplying lowerfrequency vibrational energy tomolten metalin a channel of casting wheel 30. In one embodimentof the invention, thevibrational energy isfrom a mechanical vibration generated by a transducer or other mechanical agitator. As is known from the art, a vibrator is a mechanical devicewhich generatesvibrations. A vibration isoften generated byan electric motor withan unbalanced mass on its driveshaft.Some mechanical vibrators consist ofan electromagneticdrive and a stirrer shaft which agitate&iy vertical reciprocating motion. Inone embodiment of the invention, tlwibrational energyis supplied from a vibrator(or other component) thatis capable of usingmechanical energyto create vibrational frequenciesup to but not limited to 20kHz, and preferably in a rangefrom 5-10 kHz.

Regardless ofthe vibrational mechanism,attaching a vibrator (a piezoelectric transducer, amagnetostrictive transducer, or mechanically-driven vibratoi)) housing 44 means that vibrational energy canbe transferred to the molten metalin the channel under assembly 42.

Mechanical vibrators usefulfor the invention can operate from 8,000 to 15,000 vibrations per minute,although higher and lowerfrequencies canbe used. In one embodiments the invention, thevibrational mechanism isconfigured to vibrate betweerS65 and 5,000 vibrations per second. In one embodimentof the invention, the vibrationalmechanism is configured to vibrate at even lower frequenciesdownto a fraction of a vibration every second up to the 565 vibrationsper second. Ranges of mechanically driven vibrations suitabltfor the invention include e.g., 6,000 to 9,000vibrations per minute, 8,000 to 10,000vibrations per minute, 10,000 to 12,000 vibrations per minute, 12,000to 15,000 vibrationsper minute, and 15,000 to 25,000 vibrations per minute. Ranges offnechanically driven vibrations suitablior the inventionfrom the literature reports include for example of rangesfrom 133 to 250 Hz, 200 Hz to 283 Hz (12,000 to 17,000 vibrations per minute), and4 to 250 Hz. Furthermore, a wide variety of mechanically driven oscillations can bempressed in the castingwheel 30 or the housing 44 by a simple hammer or plungerdevice driven periodicallyto strike the casting wheel 30 or the housing 44. In general, the mechanical vibrations can rangep to 10 kHz. Accordingly, rangessuitable for the mechanical vibrations usedin the invention include: 0 to 10 KHz, 10 Hz to 4000 Hz, 20 Hz to 2000 Hz, 40 Hz to 1000 Hz, 100 Hz to 500 Hz, and intermediate and combined rangesthereof, including a preferrettange of 565 to 5,000 Hz.

5 While describedabove withrespectto ultrasonic and mechanicallydriven embodiments, the inventionis not so limited to one or the other ofthese ranges, but canbe used for a broad spectrum ofvibrational energy upto 400 KHz including single frequencyand multiple frequency sources. Additionally, a combination of source^ultrasonic and mechanically driven sources, ordifferent ultrasonic sources, oriifferentmechanically driven sources or acoustic

10 energy sources to be described below^an be used.

As shown inFigure 3, casting mill 2 includes a casting wheel 30 having a containment structure 32 (e.g., a trough or channel) in the casting wheel 30 in which moltermetal is poured and a molten metal processingdevice 34. Band 36 (e.g., a steel band)confinesthe molten metal to the containment structure32 (i.e., the channel). As above, rollers 38 allowthe moltenmetal

15 processing device 34to remain stationaryas the molten metal l) solidifiesin the channel of the casting wheel and2) is conveyed away fromthe molten metalprocessing device 34.

A cooling channel46 transports a cooling medium therethrough. As beforean air wipe 52 directs air (as a safety precaution) such that any water leaking from thecooling channel is directed along a direction away from the casting source ofihe molten metal. Asbefore, a rolling

20 device (e.g., rollers 38) guides the moltenmetal processing device 34 with respect to the rotating casting wheel 30. The cooling mediunprovides cooling to the moltenmetal and the at least one vibrational energy source40 (shown inFigure 3 as a mechanical vibrator40).

As molten metal passes undeithe metal band 36 under mechanical vibrator 40, mechanically-drivenvibrational energy is supplied to the molten metalas the metal begins to

25 cool and solidify. The mechanically-driveivibrational energy in oneembodiment permits the formation of multiple small seeds, thereby producinga fine grain metal product.

In one embodiment ofthe invention, disposecfcoupled to thecooling channels 46 is at least one vibrator 40 which in the case of mechanicalvibrators provides mechanically-driven vibrational energythrough the cooling mediumas well as through the assembly 42 and the band

30 36 into the liquid metal. In one embodimentof the invention, the head of a mechanica ibrator is insertedinto cooling channel 46 to be in conductwith a liquid cooling medium. Inone embodiment ofthe invention, more than one mechanical vibratorhead or an array of mechanical vibrator heads can be insertedinto cooling channel 46to be in contactwith a liquid cooling medium. In one embodiment ofthe invention, the mechanicalvibrator head canbe attached to a wall of assembly 42.

While notbound to any particular theory, a relatively small amount of undercooling (e.g., less than 10 °C) at the bottom of the channel ofcasting wheel 30 resultsin a layer of small nuclei of purer aluminum (or other metal or alloy) being formed. The mechanically-driven vibrations create these nuclei which then are usedas nucleating agents duringsolidification resulting in a uniform grain structure. Accordingly, in oneembodiment of the inventionfhe cooling method employed ensures that a small amount ofundercooling atthe bottom of the channel results in a layer of small nuclei of the material beingprocessed. Themechanically- driven vibrations from the bottomof the channel dispersethese nuclei and/or canserve to break up dendritesthat form in theundercooledlayer. These nuclei and fragments ofdendritesare then used to form equiaxed grainsin the mold duringsolidification resulting in a uniform grain structure.

In other words, in one embodiment ofthe invention, mechanically-driven vibrations transmitted into the liquidmetal create nucleation sites in themetals or metallic alloys tcrefine the grain size. As above, the channel ofthe casting wheel 30 can be a refractory metabr other high temperature material such as copper, ironsand steels, niobium, niobiumand molybdenum, tantalum, tungsten, and rhenium, andalloys thereof includingone or more elements such as silicon, oxygen, or nitrogen whiclcan extendthe melting pointsof these materials.

Figure 3 A is a schematic ofa casting wheelhybrid configurationaccordingto one embodiment ofthe invention utilizingboth at least one ultrasonicvibrational energy source and at least one mechanically-driven vibrational energysource (e.g., amechanically-driven vibrator). The elements shown in common with those of Figure 3 are similar elements performing similar functions asnoted above. For example, the containment structure 32 (e.g., a trough or channel) noted in Figure 3 A is in the depictedcasting wheel inwhich the molten metalis poured. As above, a band (not shownin Figure 3 A) confinesthe molten metal to the containment structure 32. Here, in this embodimentof the invention, bothan ultrasonic vibrational energysource(s) and a mechanically-driven vibrational energysource(s) are selectively activatableand can be driven separately or in conjunction witheach other to provide vibrations which, upon being transmitted into the liquidmetal, create nucleation sites inthe metals or metallic alloysto refine the grain size. In various embodimentsof the invention, differentcombinationsof ultrasonic vibrational energy source(s)and mechanically-drivenvibrational energy source(s)can be arranged and utilized. Aspects of the Invention

In one aspect of the invention,the vibrational energy (from low frequency mechanically- driven vibrators in the8,000 to 15,000 vibrations per minute rangeor up to 10 KHz and/or ultrasonic frequenciesin the range of 5 to400 kHz) can be applied toa molten metal containment during cooling. In one aspect ofthe invention, the vibrationalenergy canbe applied at multiple distinct frequencies. In one aspectof the invention, thevibrational energycan be applied toa variety of metal alloys including,but not limited to those metals and alloyiisted below: Aluminum,Copper, Gold, Iron, Nickel, Platinum, Silver, Zinc, Magnesium, Titanium, Niobium, Tungsten, Manganese, Iron, and alloyand combinationsthereof; metals alloys including- Brass (Copper/Zinc), Bronze (Copper/Tin), Steefliron/Carbon), Chromalloy

(chromium), StainlessSteel (steel/Chromium), Tool Steel (Carbon/Tungsten/Manganese, Titanium (Iron/aluminum) and standardized gradesof Aluminum alloys including- 1 100,1350, 2024, 2224, 5052, 5154, 5356. 5183, 6101, 6201, 6061, 6053, 7050, 7075, 8 XXX series; copper alloysincluding, bronze (noted above)and copper alloy edwith a combination ofZinc, Tin, Aluminum, Silicon,Nickel, Silver; Magnesium alloyed with- AluminumZinc, Manganese, Silicon, Copper,Nickel, Zirconium, Beryllium, Calcium, Cerium, Neodymium, Strontium, Tin, Yttrium, rare earths; Iron andiron alloyed withChromium, Carbon, SiliconChromium, Nickel, Potassium, Plutonium,Zinc, Zirconium, Titanium,Lead, Magnesium, Tin, Scandium; and other alloys and combinations thereof.

In one aspect of the invention,the vibrational energy (from low frequency mechanically- driven vibrators in the8,000 to 15,000 vibrations per minute rangeor up to 10 KHz and/or ultrasonic frequenciesin the range of 5 to400 kHz) is coupled through a liquid medium in contact with the band into the solidifying metalunder the molten metalprocessing device 34. In one aspect of the invention, the vibrational energys mechanically coupled between565 and 5,000 Hz. In one aspectof the invention,the vibrational energyis mechanically driven ateven lower frequencies downto a fraction ofa vibration every second up to the565 vibrations per second. Inone aspect of theinvention, the vibrational energy is ultrasonically driven at frequencies fromthe 5 kHz rangeto 400 kHz. In one aspect ofthe invention, thevibrational energy is coupled throughthe housing 44 containingthe vibrationalenergy source 40. The housing 44 connects tothe other structural elementssuch as band 36 or rollers 38 which are in contact with either the wallsof the channel ordirectly with the moltenmetal. In one aspectof the invention, thismechanical coupling transmits the vibrational energy fromthe vibrational energy source into them olten metal as the metal cools. In one aspect, the cooling medium can ba liquid medium such as water. In one aspect, the cooling medium can be a gaseous medium such as one of compressedair or nitrogen. In one aspect, the cooling medium can be a phase change material. It is preferred that the cooling medium be provided at a sufficient rateto undercool the metaladjacent the band 36 (lessthan 5 to 10 °C above the liquidus temperature of the alloy or evenlower than the liquidus

temperature).

In one aspect of the inventionequiaxed grains withinthe cast product areobtained without the necessity of adding impurity particles, such astitanium boride, intothe metal or metallic alloy to increase the number of grains and improveuniform heterogeneous

solidification. Insteadof using the nucleating agents,in one aspect ofthe invention, vibrational energy can be used to create nucleating sites.

During operation, molten metalat a temperature substantially higher than thdiquidus temperature ofthe alloy flows by gravity intothe channel of castling wheel 30 andpasses under the molten metal processingdevice 34 where itis exposed to vibrationalenergy (i.e.. ultrasonic or mechanically-driven vibrations). The temperatureof the molten metal flowing into the channel of the casting dependson the type of alloy chose, therate of pour, the size ofthe casting wheel channel, among others. For aluminum alloys, thecasting temperature can rangefrom 1220 F to 1350 F, with preferredranges in betweensuch as for example, 1220 to 1300 F, 1220 to 1280 F, 1220 to 1270 F, 1220 to 1340 F, 1240 to 1320 F, 1250 to 1300 F, 1260 to 1310 F, 1270 to 1320 F, 1320 to 1330 F, with overlappingand intermediate ranges andvariances of +/- 10 degreesF also suitable. The channel of casting wheeBO is cooled to ensure that the molten metal in the channel is close to the sub-liquidustemperature (e.g., lessthan 5 to 10 °C above the liquidus temperature of the alloy or even lowerthan the liquidus temperature, although the pouring temperature can be much higher than 10 °C). During operation, the atmosphere about the molten metal may be controlledby way of a shroud (not shown) which is filled or purged for example with an inert gas such as Ar, He, or nitrogen. The moltenmetal on thecasting wheel 30 is typically ina state of thermal arrest in which the molten metal is convertingfrom a liquid to a solid.

As a result ofthe undercooling close to the sub-liquidulemperature, solidification rates are not slow enough to allow equilibrium through the solidus-liquidusinterface, which in turn results in variations in the compositionsacross the cast bar. The non-uniformity of chemical compositionresults in segregation. In addition,the amount of segregation is directly related to the diffusion coefficientsof the various elements inthe molten metal as well as the heattransfer rates. Anothertype of segregation isthe place where constituents with the lowemielting points will freeze first.

In the ultrasonicor mechanically-driven vibration embodimentsf the invention, the vibrational energy agitates the molten metal as it cools. In this embodiment|he vibrational energy is imparted with an energy which agitatesand effectively stirs the moltermetal . In one embodiment ofthe invention, the mechanically-drivenvibrational energy servesto continuously stir the molten metal as its cools. In various casting alloy processes, its desirable to have high concentrationsof silicon intoan aluminum alloy. However, athigher silicon concentrations, silicon precipitates can form. By "remixing" these precipitatesback into themolten state, elemental silicon may go at least partially back into solution. Alternatively, even if the precipitates remain,the mixingwill not result in the silicon precipitates beingegregated, thereby causing more abrasive wear on the downstream metal die and rollers.

In various metal alloy systems, the same kindof effect occurs where one component of the alloy (typicallythe higher melting point component)precipitates in a pure formin effect "contaminating" the alloywith particles of the pure component. In general, when casting an alloy, segregation occurs, whereby the concentration of solute is notmstant throughout the casting. This can be causedby a variety ofprocesses. Microsegregation, which occurs over distances comparable tothe size of the dendritearm spacing, is believed to be a resulof the first solid formed being of alower concentrationthan the final equilibrium concentration, resulting in partitioning ofthe excess solute into the liquid, so that solid formed later hasa higher concentration. Macrosegregatioroccurs over similar distances tothe size of the casting. This can be caused by a number of complex processesinvolving shrinkageeffects as thecasting solidifies, and a variation inthe density of the liquid as solute ispartitioned. It is desirableto prevent segregation duringcasting, to give a solidbillet that has uniform properties throughout.

Accordingly, some alloys whichwould benefitfrom the vibrationalenergy treatmentof the inventioninclude those alloys noted above.

Other configurations

The present invention isnot limited to the application of useof vibrational energy merely to the channel structures describedabove. In general, the vibrational energy(from low frequency mechanically-drivenvibrators inthe range up to 10 KHz and/or ultrasonicfrequencies in the range of 5 to 400 kHz) can induce nucleation at points inthe casting processwhere the molten metal is beginningto cool from the molten stateand enter the solid state (i.e., the thermal arrest state). Viewed differently, the invention,in various embodiments,combines vibrational energy from a wide variety ofsourceswith thermal management such that the moltermetal adjacent to the cooling surface is close to the liquidustemperature ofthe alloy. In these embodiments, the temperature of the moltemnetal in the channel or against theband 36 of casting wheel 30is low enough to induce nucleati on and crystal growth (dendriteformation) while the vibrational energy creates nuclei and/orbreaks up dendrites thatmay form on the surface ofthe channel in casting wheel 30.

In one embodiment ofthe invention, beneficial aspects associated with theasting process can be had without the vibrational energy sources being energized, or being energized continuously. Inone embodimentof the invention,the vibrational energysources may be energized during programmed on/off cycleswith latitude asto the duty cycle on percentages ranging from O to 100 %, 10-50%, 50-90%, 40 to 60%, 45 to 55% and all intermediate ranges in betweenthrough control of the power to the vibrational energy sources.

In another embodiment ofthe invention, vibration energy (ultrasonic omechanically driven) is directly inj ected intothe molten aluminum cast in the casting wheel priorto band 36 contactingthe molten metal. The direct application of vibrationalenergy causes alternating pressure in the melt. The directapplication of ultrasonic energy as thevibrational energyto the molten metal can cause cavitationin the molten melt.

While notbound to any particular theory, cavitation consists of the formatioiof tiny discontinuitiesor cavities inliquids, followedby their growth, pulsation, andcollapse. Cavities appear as a result of the tensile stress produced byan acoustic wavein the rarefaction phase. If the tensile stress (or negative pressure) persists afteithe cavity has been formed, the cavity will expand to several times the initial size. During cavitation in an ultrasonic field, manycavities appear simultaneously at distances less thanthe ultrasonic wavelength. In this case, the cavity bubbles retain their spherical form. The subsequent behavior ofhe cavitationbubbles is highly variable: a small fraction of the bubbles coalesces to formlarge bubbles, but almost all are collapsedby an acoustic wave in the compressionphase. During compression, some of these cavities may collapse dueto compressivestresses. Thus, when these cavitations collapse, high Shockwaves occur in the melt. Accordingly,in one embodiment of the inventionyibrational energy induced shock waves serve to break up the dendritesand other growing nuclei, thus generating new nuclei, whichin turn results in an equiaxed grain structure. In addition, in another embodimentof the invention, continuous ultrasonic vibration caneffectively homogenize the formednuclei further assistingin an equiaxed structure. In another embodiment of the invention, discontinuous ultrasonic ormechanically drivenvibrations caneffectively homogenize the formednuclei further assistingin an equiaxed structure. Figure 4 is a schematic ofa casting wheel configurationaccording to one embodiment of the invention specifically with a vibrational probe device 66having a probe (not shown) inserted directly to the molten metalcast in a casting wheel 60. Theprobe would be of a construction similar to that known inthe art for ultrasonicdegassing. Figure 4 depicts a roller62 pressing band 68 onto a rim of the casting wheel60. The vibrational probe device 66 couples vibrational energy (ultrasonicor mechanically drivenenergy) directly or indirectly into moltemnetal cast into a channel (not shown)of the casting wheel60. As the casting wheel 60 rotates

counterclockwise,the molten metal transits under roller 62 and comes in contactwith optional moltenmetal cooling device 64. This device 64 can be similar tothe assembly 42 ofFigures 2 and 3, but without thevibrators 40. This device 64 can be similar to the moltenmetal processing device 34 ofFigure 3, but without the mechanical vibrators 40.

In this embodiments shownin Figure 4, a molten metal processing device foa casting mill utilizes at least one vibrational energy source(i.e., vibrational probe device 66)which supplies vibrational energy by a probe inserted intomolten metal castin the castingwheel (preferably butnot necessarily directly intomolten metal cast inthe castingwheel) while the moltenmetal in the castingwheel is cooled. A support deviceholdsthe vibrational energy source (vibrational probe device66) in place.

In another embodiment ofthe invention, vibrational energy carbe coupled into the moltenmetal while it is being cooled throughan air or gas as mediumby use of acoustic oscillators. Acoustic oscillators (e.g., audio amplifiers) canbe used to generate andtransmit acoustic waves into the moltenmetal. In thisembodiment, theultrasonic or mechanically-driven vibrators discussedabove wouldbe replaced with or supplemented by theacoustic oscillators. Audio amplifiers suitable forthe invention wouldprovide acoustic oscillations froml to 20,000 Hz Acousticoscillations higheror lowerthan this rangecan be used. Forexample, acoustic oscillationsfrom 0.5 to 20 Hz; 10 to 500 Hz, 200 to 2,000 Hz, 1,000 to 5,000 Hz, 2,000 to 10,000 Hz, 5,000 to 14,000 Hz, and 10,000 to 16,000 Hz, 14,000 to 20,000 Hz, and 18,000 to 25,000 Hz can be used. Electroacoustic transducers canbe used to generate andtransmit the acoustic energy.

In one embodiment ofihe invention, the acoustic energy caibe coupled through a gaseous medium directly into the molten metal where the acoustic energy vibrates themolten metal. In one embodimentof the invention, the acoustic energy canbe coupled through a gaseous medium indirectly into the molten metal wherethe acoustic energy vibrates theband 36 or other support structure containing the moltenmetal, whichin turn vibrates the moltenmetal. Besides use ofthe present invention' svibrational energy treatmentin the continuous wheel -type castingsy stems described above,the presentinventionalso has utility in stationary molds and in vertical casting mills.

For stationary mills, themolten metal would be poured into a stationary cast 62 such as the one shown in Figure 5, which itself has a molten metalprocessingdevice 34 (shown schematically). Inthis way, vibrational energy (from low frequency mechanically-driven vibrators operating up to 10 KHz and/or ultrasonicfrequencies inthe range of 5 to 400 kHz) can induce nucleation at points in the stationary cast wherethe molten metal is beginning to cool from the molten state and enterthe solid state (i.e., the thermal arreststate).

Figures 6A-6D depict selected components ofa vertical castingmill. More details of these componentsand other aspects of a vertical casting mill are found in U.S. Pat. No.

3,520,352 (the entire contentsof which are incorporated herein by reference). Ashown in Figures 6A-6D, the vertical casting mill includesa molten metal casting cavity 213, which is generally square in the embodimentillustrated, but which may be round, elliptical, polygonalor any other suitable shape, and which is boundedby vertical, mutually intersectingfirst wall portions 215, and second or corner wall portions, 217, situated in the topportion of themold. A fluid retentive envelope 219 surrounds the walls 215and corner members 217of the casting cavity in spaced apart relation thereto. Envelope219 is adapted to receive a cooling fluid, such as water, via an inlet conduit 221, and to dischargethe cooling fluid via an outletconduit 223.

While the firstwall portions215 are preferably made of a highly thermal conductive material such as copper, the second or cornerwall portions217 are constructedof lesser thermally conductive material, such as, for example, a ceramicmaterial. As shownin Figures 6A-6D, the cornerwall portions217 have a generally L-shaped or angularcross section, andthe vertical edges of each corner slope downwardly and convergently toward each other .Thus, the corner member217 terminates at some convenient! evel in themold above of the discharged ofthe mold which is between the transverse sections.

In operation, molten metal flows from a tundish 245 into a castingnold that reciprocates vertically and a cast strand of metal is continuously withdrawn from themold. The moltenmetal is firstchilled in the mold upon contacting the cooler moldwalls in what maybe considered as a first cooling zone. Heat is rapidly removed from the moltenmetal in this zone,and a skin of material is believed to form completely around a central pool of molten metal.

In one embodiment ofthe invention, the vibrational energy sources (vibrators 40 illustrated schematically onlyon Figure 6D for the sake of simplicity) would be disposedin relation to the fluid retentive envelope 219 and preferably into the cooling mediumcirculating in the fluid retentive envelope 219. Vibrational energy (from low frequency mechanically-driven vibrators in the 8,000 to 15,000 vibrations per minuterange and/orultrasonic frequencies in the range of 5 to400 kHz and/or the above-notedacoustic oscillators) would induce nucleation at points in thecasting process where the molten metal is beginning ίωοοΐ from the molten state and enter the solid state (i.e., the thermal arrest state)as the molten metal is converting froma liquid to a solid and as the cast strandof metal is continuously withdrawn fronthe metal casting cavity 213.

In one embodiment ofthe invention, the above-described ultrasonic grain refining is combinedwith above-notedultrasonic degassing toremove impurities from themolten bath before the metal is cast. Figure 9 is a schematic depicting an embodiment^ the invention utilizing both ultrasonic degassingand ultrasonicgrain refinement. As showrtherein, a furnace is a source of moltenmetal. The molten metal is transported in a laundefrom the furnace. In one embodimentof the invention, an ultrasonic degasser is disposed in thepath of launder prior to the molten metalbeing provided intoa casting machine (e.g., casting wheel) containing an ultrasonic grain refiner (not shown). In one embodiment,grain refinement inthe casting machine need not occur at ultrasonic frequencies but ratheicould be at one or more of the other mechanically driven frequenciesdiscussed elsewhere.

While not limited to the following specific ultrasonicdegassers, the ' 336patent describes degas sers which are suitable for different embodimentsof the present invention. Onesuitable degasser would be an ultrasonic device havingan ultrasonic transducer; an elongated probe comprising afirst end and a second end, the first end attachedto the ultrasonic transducerand the second end comprisinga tip; and a purging gas delivery system, wherein the purginggas delivery system may comprise a purging gas inlet and a purging gas outlet. In some embodiments, the purging gas outlet may be within about 10 cm (or 5 cm, or 1 cm) ofthe tip ofthe elongated probe, while in other embodiments,the purging gas outlet may be atthe tip of the elongated probe. In addition, the ultrasonic device may comprise multiple probe assemblies and/or multiple probes per ultrasonic transducer.

While not limited to the following specific ultrasonicdegassers, the ' 397patent describes degas sers which are also suitable for differentembodiments ofthe present invention. One suitable degasserwould be an ultrasonic devicehaving an ultrasonic transducer; a probe attached to the ultrasonic transducer, the probe comprising tip; and a gas delivery system, the gas delivery systemcomprisinga gas inlet, a gas flowpath through the probe, and a gas outlet at the tip of the probe. In an embodiment, the probe maybe an elongated probe comprising a first end and a second end, the first end attached to the ultrasonictransducer andthe second end comprising atip. Moreover, the probe maycomprise stainless steel, titanium, niobiuma ceramic, and the like, or a combination ofany of these materials. Inanother embodiment,the ultrasonic probe may be a unitary SIALON probe with the integrated as delivery system therethrough. In yet another embodiment, the ultrasonic devicmay comprise multiple probe assemblies and/or multipleprobes per ultrasonic transducer.

In one embodiment ofthe invention, ultrasonic degasification usingor example the ultrasonic probes discussedabove complements ultrasonic grain refinement. In various examples of ultrasonic degasification^a purging gas is addedto the moltenmetal e.g., by way of the probes discussedabove at a rate in a range from about 1 to about 50 L/min. By a disclosure that the flow rate is in a range from about 1 to about 50 L/min, the flowrate may be about 1 , about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 11, about 12, about 13, about 14, about 15, about 16, about 17, about 18, about 19, about 20, about 21, about 22, about 23, about 24, about 25, about 26, about 27, about 28, about 29, about 30, about 31, about 32, about 33, about 34, about 35, about 36, about37, about 38, about 39, about 40, about 41, about 42, about 43, about 44, about 45, about 46, about 47, about 48, about 49, or about 50 L/min. Additionally ,the flow rate may be within any range from about 1 to about 50 L/min (for example, the rate is in a range from about 2 to about 20 L/min), andthis also includes any combinationof ranges between about 1 and about 50 L/min. Intermediate ranges are possible. Likewise, all other ranges disclosedherein should beinterpreted in a similar manner.

Embodiments of thepresent invention relatedto ultrasonic degasification andultrasonic grain refinementmay provide systems, methods, and/or devicefbr the ultrasonic degassing of molten metals included but not limited to, aluminum, copper,steel, zinc, magnesium, and the like, or combinationsof these and other metals (e.g., alloys). The processingor casting of articles from a molten metal may require a bath containing themolten metal, andthis bath ofthe molten metal may be maintained at elevated temperatures.For instance, moltencopper may be maintained at temperatures of around 1100° C, while molten aluminum maybe maintained at temperatures of around 750° C.

As used herein, the terms "bath," "moltenmetal bath," and thelike are meantto encompassany containerthat might contain a moltenmetal, inclusive of vessel, cruciblejrough, launder, furnace, ladle, and so forth. The bath and molten metalbath terms are used to encompassbatch, continuous, semi-continuous,etc, operations and, for instance, where the moltenmetal is generally static(e.g., often associatedwith a crucible) and where the molten metal is generally in motion (e.g., often associated with a launder). Many instalments or devices maybe used to monitor, to test, orto modify the conditions of the molten metal in the bath, as well as for the final production or castingof the desired metal article. There is a need for these instruments or devicesto better withstand theelevated temperatures encounteredin molten metal baths, beneficially having a longer lifetime and limited to no reactivity with the molten metal, whether themetal is (or themetal comprises) aluminum, or copper, or steel,or zinc, or magnesium,and so forth.

Furthermore, molten metalsmay have one ormore gasses dissolvedin them, andthese gasses may negatively impact the final productionand casting of the desired metal article,and/or the resulting physical propertiesof the metal articleitself. Forinstance, the gas dissolved in the moltenmetal may comprise hydrogen, oxygen,nitrogen, sulfur dioxide,and the like, or combinationsthereof. Insome circumstances,it may be advantageous to removethe gas, or to reduce the amount of the gas in the molten metal. As an example, dissolved hydrogen mayje detrimental inthe casting of aluminum (or copper, or other metal or alloy) and, therefore, the propertiesof finishedarticles produced from aluminum (or copperpr othermetal or alloy)may be improved byreducing the amount of entrained hydrogen in the moltenbath of aluminum (or copper, or other metal or alloy). Dissolvedhydrogen over 0.2 ppm, over 0.3 ppm, orover 0.5 ppm, on a mass basis, may have detrimental effectson the castingrates and the quality of resulting aluminum (or copper, or other metal or alloy) rods and other articles. Hydrogen may enter the molten aluminum (or copper, or other metal or alloy) bath by its presence in the atmosphere abovethe bath containing themolten aluminum (or copper, or other metal or alloy), or it may be presentin aluminum (or copper, or other metal or alloy) feedstock starting material used in the molten aluminum (or copper, or other metal or alloy) bath.

Attempts to reducethe amounts of dissolved gassesin molten metalbaths have not been completely successful. Oftenjhese processes in the pastinvolved additional and expensive equipment, aswell as potentially hazardous materials. Forinstance, a process used in themetal casting industry to reduce the dissolved gas content of a molten metalmay consist of rotors made of a material such as graphite, and these rotors maybe placed within the molten metalbath. Chlorinegas additionally maybe added to the moltenmetal bath at positions adjacent to the rotors within the molten metal bath. While chlorine gas addition may be successful in reducing, for example, theamount of dissolved hydrogenin a molten metal bathin some situations, this conventional processhas noticeable drawbacks, not theleast of which are cost, complexity, and the use of potentially hazardous and potentially environmentally harmful chlorine gas.

Additionally, molten metalsmay have impurities present in them,and these impurities may negatively impact the final production and casting of the desired metal article, and/or the resulting physical propertiesof the metal articleitself. For instance, the impurityin the molten metal may comprise an alkalimetal or other metal that is neitheirequired nor desired to be present in themol ten metal. Small percentagesof certain metals are present in various metal alloys, and such metals would notbe considered to beimpurities. As non-limiting examples, impurities may comprise lithium, sodium, potassium, lead, andthe like, or combinations thereof. Various impurities may enter a molten metal bath(aluminum, copper, or other metal or alloy) by their presence in theincoming metal feedstock starting material used in the moltemetal bath.

Embodiments of thisinvention relatedto ultrasonic degasifi cation andultrasonic grain refinement mayprovide methods for reducing an amount ofa dissolvedgas in a moltenmetal bath or, in alternative language, methods fordegassing moltenmetals. One such method may comprise operating an ultrasonic device in the molten metalbath, and introducing a purginggas into the moltenmetal bath in close proximity to the ultrasonic device. The dissolved gasmay be or may comprise oxygen, hydrogen, sulfur dioxideand the like, or combinations thereof. For example, the dissolvedgas may be or may comprise hydrogen. Themolten metalbath may comprise aluminum, copper, zinc, steel, magnesium, andthe like, or mixtures and/or

combinationsthereof(e.g., including various alloysof aluminum, copper,zinc, steel,

magnesium, etc.). In some embodiments related to ultrasonidegasificationand ultrasonic grain refinement, the molten metalbath may comprise aluminum,while in other embodiments, the moltenmetal bath may comprise copper. Accordingly, the moltermetal in thebath may be aluminum or, alternatively, the molten metal maybe copper.

Moreover, embodimentsof this inventionmay provide methodsfor reducing an amount of an impurity presentin a moltenmetal bath or, in alternative language, methodsfor removing impurities. One such method related to ultrasonic degasificati on andultrasonic grain refinement may comprise operating an ultrasonic device inthe molten metalbath, and introducing a purging gas into the moltenmetal bath in close proximityto the ultrasonic device. The impurity may be or may comprise lithium, sodium, potassium, lead, and the like, or combinations thereofFor example, the impurity may be or may comprise lithium or, alternatively, sodium. The molten metal bath may comprise aluminum, copper, zinc, steeknagnesium, and the like, or mixtures and/or combinationsthereof (e.g., including various alloys ofaluminum, copper,zinc, steel, magnesium, etc.). In some embodiments, the molten metabath may comprise aluminum,while in other embodiments,the moltenmetal bath may comprise copper. Accordingly,the molten metal in the bath may be aluminum or, alternatively, the moltenmetal maybe copper.

The purging gas relatedto ultrasonic degasificationand ultrasonic grain refinement employedin the methods of degassing and/ormethods of removing impuritiesdisclosed herein may comprise oneor more of nitrogen, helium, neon, argon, krypton, and/or xenon, but is not limited thereto. It is contemplated that any suitablegas may be used as a purging gas, provided that the gas does not appreciably react with, or dissolve irtjie specific metal(s)in the molten metal bath. Additionally, mixtures ocombinations of gases maybe employed. According to some embodimentsdisclosed herein, the purging gas may be or may comprise an inert gas; alternatively, the purging gas maybe or may comprise anoble gas; alternatively ,the purging gas may be or may comprise helium, neon, argon,or combinations thereofalternatively, the purging gas may be or maycomprise helium; alternatively, the purging gasnay be or may comprise neon; or alternatively, the purging gas maybe or may comprise argon. Additionally, Applicants contemplate that,in some embodiments,the conventional degassingcechnique canbe used in conjunctionwith ultrasonic degassingprocesses disclosed herein. Accordingl^the purginggas may further comprise chlorine gas in some embodiments, such as thjEse of chlorine gas asthe purging gas alone or in combination withat least one of nitrogen, helium, neon^rgon, krypton, and/or xenon.

However, inother embodiments of this inventionniethods related to ultrasonic degasificationand ultrasonic grain refinement fordegassing or forreducing an amount of a dissolvedgas in a molten metalbath may be conducted inthe substantial absence of chlorin¾as, or with no chlorine gas present. As used herein, a substantial absencemeans that no more than 5% chlorine gas by weight maybe used, based onthe amount of purging gasused. In some embodiments,the methods disclosed hereinmay comprise introducinga purging gas, and this purging gas may be selectedfrom the group consisting ofnitrogen, helium, neon,argon, krypton, xenon, and combinationsthereof.

The amount of the purginggas introduced into the bath offnolten metal may vary depending on a number of factors. Often, the amount of the purging gas related to ultrasonic degasificationand ultrasonic grain refinement introduced in a method of degassing molten metals (and/or in a method of removing impurities frommolten metals)in accordance with embodimentsofthis inventionmay fall withina range from about 0.1 to about 150 standard liters/min (L/min). In some embodiments,the amount of thepurging gas introduced may be in a range from about0.5 to about 100 L/min, from about 1 to about 100 L/min, fromabout 1 to about 50 L/min, from about 1 to about 35 L/min, from about 1 to about 25 L/min, fromabout 1 to about 10 L/min, from about 1.5 to about 20 L/min, from about 2 to about 15 L/min,or from about 2 to about 10 L/min. These volumetric flow rates are in standard litersper minute, i.e., at a standard temperature (21.1° C.) and pressure(101 kPa). In continuous or semi-continuousmolten metal operations, the amount of thepurging gas introduced intothe bath of moltenmetal may vary based onthe moltenmetal output or production rate. Accordingly, the amount of the purginggas introduced in a method of degassingmolten metals (and/orin a method ofremoving impurities frommolten metals)in accordance withsuch embodimentsrelated to ultrasonic degasificationand ultrasonic grain refinement mayfall within a range from about 10 to about 500 mL/hr of purging gas per kg/hr of molten metal (mL purging gas/kg moltenmetal). In some embodiments, thffatio of the volumetric flow rate of the purging gas to the output rate of the moltenmetal may be in a range from about 10 to about 400 mL/kg; alternatively, from about 15 to aboutSOO mL/kg;

alternatively, fromabout 20 to about 250 mL/kg; alternatively,from about 30 to about 200 mL/kg; alternatively, fromabout 40 to about 150 mL/kg; or alternatively, from about 50 to about 125 mL/kg. As above, the volumetric flow rate of thepurging gas is at a standard temperature (21.1° C.) and pressure (101 kPa).

Methods for degassing molten metalsonsistent withembodimentsof this invention and related to ultrasonic degasificationand ultrasonic grain refinement may be effective in removing greaterthan about 10 weightpercent ofthe dissolvedgas present in the moltenmetal bath, i.e., the amount of dissolvedgas in the molten metal bath maybe reduced by greater thanabout 10 weight percent from the amount of dissolved gas present before thdegassingprocess was employed. In some embodiments, the amount of dissolvedgas present maybe reduced by greater than about 15 weight percent, greater than about 20 weight percent,greater than about 25 weightpercent, greater than about 35 weight percent, greater than abour50 weightpercent, greaterthan about 75 weightpercent, or greater than about 80weightpercent, from theamount of dissolvedgas present beforethe degassing method was employed. Fomstance, if the dissolvedgas is hydrogen, levels of hydrogenin a molten bath containing aluminum or copper greaterthan about 0.3 ppm or 0.4 ppm or 0.5 ppm (on amass basis) maybe detrimental and, often, the hydrogen content in the molten metal may be about 0.4 ppm, about0.5 ppm, about 0.6 ppm, about 0.7 ppm, about 0.8 ppm, about 0.9 ppm, about 1 ppm, about 1.5 ppm, about 2 ppm, or greaterthan 2 ppm. It is contemplated thatemploying themethods disclosed inembodiments of this inventionmay reduce the amount of the dissolved gasin the moltenmetal bath to less than about 0.4 ppm; alternatively, to less than about0.3 ppm; alternatively, toless than aboutO.2 ppm; alternatively, to within a range from about 0.1 to about 0.4 ppm;alternatively, to within a range from aboutO.1 to about 0.3 ppm; or alternatively, to withina range fromabout 0.2 to about 0.3 ppm. In these and other embodiments, the dissolved gasnay be or may comprise hydrogen, and the molten metalbath may be or may comprise aluminum and/oicopper. Embodiments of thisinvention relatedto ultrasonic degasifi cation andultrasonic grain refinement anddirected to methods oidegassing (e.g., reducing the amounbf a dissolvedgas in bath comprisinga molten metal)or to methods ofremovingimpurities may comprise operating an ultrasonic device in the moltenmetal bath. The ultrasonicdevice maycomprisean ultrasonic transducer and an elongated probe, andthe probemay comprise a first end and a second end. The first end may be attached to the ultrasonic transducer andthe second end may comprise a tip, and the tip of the elongated probe may comprise niobium. Specificson illustrative and non- limiting examples of ultrasonic devices thatmay be employedin the processes andmethods disclosedherein are describedbelow.

As it pertains to anultrasonic degassingprocess or toa process forremoving impurities, the purging gas may be introducedinto the moltenmetal bath, for instance, ata location near the ultrasonic device. In one embodiment, the purginggas may be introduced into the moltenmetal bath at a location near the tip of the ultrasonic device. In one embodiment,the purging gasmay be introducedinto the moltenmetal bath within about 1 meter of the tip of the ultrasonic device, such as, for example, within about 100 cm, within about50 cm, within about 40 cm,within about 30 cm, within about 25 cm, or within about 20 cm, of the tip of the ultrasonic device. In some embodiments,the purginggas may be introduced intothe molten metalbath within about 15 cm of the tip of the ultrasonic device; alternatively, within about! 0 cm; alternatively, within about 8 cm; alternatively, within about 5 cm; alternatively, within about 3 cm; alternatively, within about 2 cm; or alternatively, within about 1 cm. In a particular embodiment, the purging gas may be introduced intothe molten metal bath adjacent to or through the tip of the ultrasonic device.

While not intending to be bound bythis theory, the use of an ultrasonic deviceand the incorporation of a purging gas in close proximity, resultsin a dramatic reductionin the amount of a dissolvedgas in a bath containing moltenmetal. The ultrasonic energy producecby the ultrasonic device may create cavitation bubblesin the melt, into which the dissolvedjas may diffuse. However, in the absenceofthe purging gas, many ofthe cavitationbubbles may collapse prior to reaching the surface ofthe bath of molten metal. Thepurging gas may lessen the amount of cavitation bubblesthat collapse beforereaching the surface,and/or may increase the size of the bubbles containing the dissolved gas,and/or may increase the number of bubbles in the molten metalbath, and/or may increasethe rate of transport of bubbles containing dissolvedgas to the surface ofthe molten metal bath. The ultrasonic device may create cavitation bubbles within closeproximityto the tip of the ultrasonic device. For instance, foran ultrasonic device having a tipwith a diameter of about 2 to 5 cm,the cavitation bubbles maybe within about 15 cm, about 10 cm, about 5 cm, about2 cm, or about 1 cm of the tip of the ultrasonic devicebefore collapsing. If the purging gas is added afe distance thatis too far from the tip ofthe ultrasonicdevice, the purging gas maynot be able to diffuse into tha;avitation bubbles. Hence, in embodiments related to ultrasonidegasificationand ultrasonic grain refinement, the purging gas isintroducedinto the molten metal bathwithin about 25 cm or about 20 cm ofthe tip of theultrasonic device, and more beneficially, within about 15 cmyithin about 10 cm, within about 5 cm, withinabout 2 cm, or withinabout 1 cm, of the tip of the ultrasonic device.

Ultrasonic devices inaccordance withembodiments of this invention ma be in contact with molten metals such as aluminum or copper, forexample, as disclosed in U.S. Patent Publication No.2009/0224443, which is incorporated hereinby reference in its entirety. In an ultrasonic device for reducing dissolved gas content (e.g. ydrogen) in a moltenmetal, niobium or an alloy thereof may be usedas a protective barrierfor the device when it is exposedto the moltenmetal, or as a componentof the devicewith direct exposure tothe molten metal.

Embodiments of thepresent invention relatedto ultrasonic degasifi cation andultrasonic grain refinementmay provide systems and methodsfor increasingthe life of components directly in contactwith molten metals. For example, embodiments ofhe invention mayuse niobium to reduce degradation of materialsin contact with molten metals, resulting in significant[uality improvementsin end products. In other words, embodiments ofthe invention may increase the life ofor preserve materials or components incontactwith moltenmetals by usingniobium as a protectivebarrier. Niobium may have properties, forexample its high melting pointftiat may help provide theaforementionedembodiments ofthe invention. In addition,niobium also may form a protective oxide barrierwhen exposedto temperatures of about 200° Cand above.

Moreover, embodimentsof the invention related to ultrasonidegasificationand ultrasonic grain refinementmay provide systems andmethods forincreasingthe life of components directlyin contactor interfacing with molten metals. Because niobiurrhas low reactivity with certain molten metals, using niobium may prevent a substrate material from degrading. Consequently, embodiments of the inventionelated to ultrasonic degasificationand ultrasonic grain refinementmay use niobium to reduce degradation of substrate materials resulting in significant quality improvements inend products. Accordingly, niobiumin association withmolten metalsmay combine niobium's highmelting pointand its low reactivity with molten metals, such as aluminum and/or copper.

In some embodiments, niobiumor an alloy thereofmay be usedin an ultrasonicdevice comprising anultrasonic transducer and an elongated probe. The elongated probe may comprise a first endand a second end, wherein the firsend may be attachedto the ultrasonictransducer and the second endmay comprisea tip. In accordance with this embodiment, th&p ofthe elongated probe maycomprise niobium(e.g., niobium or an alloy thereof). The ultrasonic device may beused in an ultrasonic degassing process, as discussedtbove. The ultrasonic transducer may generateultrasonic waves, and the probe attachedo the transducermay transmit the ultrasonic wavesinto a bath comprisinga molten metal, such as aluminum, copper,zinc, steel, magnesium, and thdike, or mixtures and/or combinations thereoi(e.g., including various alloys of aluminum, copper, zinc, steel, magnesium, etc.).

In various embodiments ofthe invention, a combination of ultrasonic degassing and ultrasonic grain refinementis used. The use ofthe combination of ultrasonic degassing and ultrasonic grain refinementprovides advantages bothseparately and in combination, as described below. While not limited to the following discussion, thefollowingdiscussion providesan understanding of the unique effects accompanying a combination ofihe ultrasonic degassing and ultrasonic grain refinement, leading to improvement(s) in theoverall quality of a cast product which would notbe expected when eitherwas used alone. These effectshave been realized and by the inventorsin their development ofthis combined ultrasonic processing.

In ultrasonic degassing, chlorine chemicals (utilize^hen ultrasonic degassing is not used) are eliminated from the metal casting process. When chlorine as a chemicals present in a molten metal bath, it can react and form strong chemicalbonds with otherforeign elementsin the bath such as alkalis which mightbe present. Whenthe alkalis are present, stable salts are formed in the molten metalbath, which could lead to inclusions in the cast metal product which deteriorates itselectrical conductivity and mechanical properties. Without ultrasonic grain refinement, chemical grain refiners suchas titanium boride are used, but these materials typically contain alkalis.

Accordingly, withultrasonic degassing eliminating hlorine as a processelement and with ultrasonic grain refinementeliminating grain refiners(a source of alkalis),the likelihood of stable salt formation and the resultant inclusion formation in thecast metal product is reduced substantially. Moreover, the elimination ofthese foreign elements as impurities improves the electrical conductivity ofthe cast metal product. Accordingly ,in one embodiment of the invention, the combination of ultrasonic degassing and ultrasonicgrain refinement means that the resultant cast product has superior mechanical and electrical conductivity properties, as two ofthe major sources of impurities are eliminated without substituting one foreign impurity for another. Another advantageprovided by the combination ofultrasonic degassing and ultrasonic grain refinementrelates to the fact that both the ultrasonic degassing and ultrasonic grain refinement effectively "stir'the molten bath, homogenizing the moltermaterial. When an alloy of the metal is being melted and then cooledto solidification, intermediate phasesf the alloys can exist because of respectivedifferences in the melting oints of different alloy proportions. In one embodimentof the invention, both the ultrasonicdegassing and ultrasonic grain refinement stir and mix the intermediatephasesback into the molten phase.

All of these advantages permit one to obtaiia product which is small-grained, having fewer impurities, fewer inclusions,better electrical conductivity, better ductilitjand higher tensile strength than would be expected when either ultrasonic degassing or ultrasonic grain refinement wasused, or when either or both were replaced with conventional chlorine processing or chemical grain refiners were used.

Demonstration Ultrasonic Grain Refinement

The containment structures showrin Figures 2 and 3 and 3 A have beenused having a depth of 10 cm and a width of 8 cm forming a rectangular trough orchannel in the castingwheel 30. The thickness of the flexiblemetal band was6.35 mm. The width of theflexible metal band was 8 cm. The steel alloy used for the bandwas 1010 steel. An ultrasonic frequency of20 KHz was used at a power of 120 W (per probe) being suppliedto one or twotransducers having the vibrating probes in contact with water in the cooling medium. A section ofa copper alloy casting wheel was used as the mold. As a cooling medium, waterwas supplied atnear room temperature andflowing at approximately 151iters/min through channels 46.

Molten aluminum was poured at a rate of40 kg/min producing a continuous aluminum cast showing properties consistentwith an equiaxed grain structure although no grain refiners were added. Indeed, approximately 9 million pounds of aluminum rod have beencast and drawn into final dimensionsfor wire and cable applications usingthis technique.

Metal Products

In one aspect of the present inventionproducts including a cast metallic compositioncan be formedin a channel of a casting wheel or in the casting structuresdiscussed abovewithout the necessity of grain refiners and still having sub-millimeter grain sizes. Accordingly^ cast metallic compositionscan be made with less than 5% of the compositions including the grain refiners and still obtain sub-millimeter grain sizes. The cast metallic compositionscan be made with less than 2% of the compositionsincluding the grainrefiners and still obtain sub-millimeter grain sizes. The castmetallic compositionscan be made with less than 1% of thecompositions including the grainrefiners and stillobtain sub-millimeter grain sizes. In a preferred composition, the grain refiners are less thafil.5 % or less than 0.2% or less than0.1%. The cast metallic compositionscan be made withthe compositions including no grain refiners andtill obtain sub-millimeter grain sizes.

The cast metallic compositions can have a variety of sub-millimeter grain sizes depending on a number of factorsincludingthe constituents of the "pure" or alloyed metal, the pour rates, the pour temperatures, the rate of cooling. The listof grain sizes availableto the presentinventionincludes the following. Foraluminum and aluminum alloys, grain sizes range from 200 to 900 micron, or 300 to 800 micron, or 400to 700 micron, or 500 to 600 micron. For copper and copper alloys, grain sizes rangefrom 200 to 900 micron, or 300 to 800 micron, or 400 to 700 micron, or 500 to 600 micron. For gold,silver, or tin or alloys thereof, grain sizes range from 200 to 900 micron, or 300 to 800 micron, or 400 to 700 micron, or 500 to 600 micron. For magnesium or magnesium alloys,grain sizes rangefrom 200 to 900 micron, or 300 to 800 micron, or 400 to 700 micron, or 500 to 600 micron. While givenin ranges, the invention is capable of intermediate valuesas well. In one aspectof the present invention, small concentrations(less than 5%) of the grain refiners maybe added to further reduce the grain size to valuesbetween 100 and 500 micron. The castmetallic compositions caninclude aluminum, copper, magnesium, zinc, lead, gold, silver, tin, bronze, brass, and alloys thereof.

The cast metallic compositions can bedrawn or otherwise formed into bar stock, rod, stock, sheet stock, wires, billets,and pellets.

Computerized Control

The controller500 in Figures 1, 2, 3, and 4 can be implemented byway of the computer system 1201 shownin Figure 7. The computer system 1201 may be used as thecontroller 500 to control the castingsystems notedabove or any other casting system or apparatusemploying the ultrasonic treatmentof thepresentinvention. Whiledepicted singularlyin Figures 1, 2, 3, and 4 as one controller, controllei500 may include discrete and separate processors in communication witheach other and/or dedicated toa specific controlfunction.

In particular, the controller 500can be programmedspecificallywith control algorithms carrying out the functions depicted by the flowchart in Figure 8.

Figure 8 depictsa flowchartwhose elementscan be programmed or stored in a computer readable medium or in one of the data storage devices discussed elow. The flowchart of Figure 8 depicts a method of the resentinvention forinducingnucleation sites in a metalproduct. At step element 1802, the programmedelement woulddirectthe operation of pouring molten metal, into a molten metal containment structure. At step element 180 he programmed element would direct theoperation of cooling the molten metal containmemtructure for example by passage ofa liquid medium through a cooling channel inproximity to themolten metal containment structure. At step element 1806, the programmed elementwould direct the operation of coupling vibrational energy into the molten metal. In this element, tbebrational energy would havea frequency andpower whichinducesnucleati on sites in themolten metal, as discussed above.

Elements such asthe molten metal temperature,pouring rate, cooling flow throug he cooling channel passages, and mold cooling and elements related tcthe control anddraw of the cast product through the mill, including control of the power andfrequency of the vibrational energy sources, would be programmed withstandard software languages (discussed below)o produce special purpose processors containingnstructionsto apply the method of the present inventionfor inducing nucleationsites in a metal product.

More specifically,computer systeml201 shown in Figure 7 includes a busl202 or other communication mechanismfor communicatinginformation, anda processor 1203 coupled with the bus 1202 for processingthe information. The computer system 1201 alsoincludes a main memory 1204, suchas a random accessmemory (RAM) or otherdynamic storage device(e.g., dynamic RAM (DRAM), staticRAM (SRAM), and synchronous DRAM (SDRAM)), coupled to the bus 1202 forstoring information andinstructions tobe executedby processor 1203. In addition, the main memory 1204 maybe used for storing temporary variables or other intermediate informationduring the execution of instructionsby the processorl203. The computer systeml201 further includesa read only memory (ROM) 1205 or other staticstorage device (e.g., programmable readonly memory (PROM), erasable PROM(EPROM), and electrically erasablePROM (EEPROM)) coupled to thebus 1202 for storingstatic information and instructions for theprocessor 1203.

The computer system 1201 alsoincludes a disk controller 1206coupled to the busl202 to control one or more storage devices fostoring information and instructions, such as a magnetic hard disk 1207, and a removable mediadrive 1208 (e.g., floppydisk drive, read-only compact disc drive, read/write compactlisc drive, compact disqukebox, tape drive, and removable magneto-optical drive). The storage devices may be added to thesomputer system 1201 using an appropriate deviceinterface (e.g., small computer system interfac(SCSI), integrated deviceelectronics(IDE), enhanced-IDE(E-IDE), direct memoryaccess (DMA), or ultra-DMA). The computer system 1201 mayalso include special purpose logicdevices (e.g., application specific integrate ircuits (ASICs)) or configurable logicdevices (e.g., simple programmable logic devices (SPLDs), compleyrogrammable logic devices(CPLDs), and field programmable gate arrays(FPGAs)).

The computer system 1201 mayalso includea display controller 1209coupled to the bus 1202 to control a display,such as a cathode ray tube (CRT) or liquid crystal display (LCD), for displaying information to a computer user.The computer system includes input devices, such as a keyboard and a pointing device, forinteracting with a computeruser (e.g. a user interfacingwith controller 500)and providing information to the processoi203.

The computer system 1201 performsa portion or all of the processing stepsof the invention (such as for example those described inelation to providing vibrational energyto a liquid metal in a state of thermal arrestjin response to theprocessor l203 executing one or more sequences of one or more instructionttontained in a memory, such as thonain memory 1204. Such instructions may be read into the main memoryl204 from another computer readable medium, such as a hard disk 1207 or a removablemedia drive 1208. One or more processors in a multi-processing arrangementmay also be employed to executethe sequences of instructions contained inmain memory 1204. In alternative embodiments, hard-wirecbircuitry may be used in place of or in combination withsoftware instructions. Thus,embodiments are notlimited to any specificcombination of hardware circuitry and software.

The computer system 1201 includesat least one computer readable medium omiemory for holding instructions programmed according the teachingsof the invention and for containing data structures,tables, records, or other data describedherein. Examples of computer readable mediaare compact discs, harddisks, floppydisks, tape, magneto-optical disks, PROMs (EPROM, EEPROM, flash EPROM),DRAM, SRAM, SDRAM, or any other magnetic medium, compact discs (e.g., CD-ROM),or any other opticalmedium, or otherphysical medium, a carrier wave (described below), oiany other mediumfrom which a computercan read.

Stored on any one or on a combination ofcomputer readable media, the invention includes software forcontrolling the computer system 1201, for driving device or devicesfor implementing the invention^nd for enabling the computer system 1201 to interact with a human user. Such software may includebut is not limited to, devicedrivers, operating systems, developmenttools, and applications software. Such computer readable media further includes the computerprogram product of the invention foperformingall or a portion (if processing is distributed) ofthe processing performedn implementing the invention. The computer code devices ofihe inventionmay be any interpretable or executable code mechanism, includingbut not limited to scripts, interpretable programs, dynamic link libraries (DLLs), Java classes, andcompleteexecutableprograms. Moreover, parts ofthe processing of the inventionmay be distributed for better performance,reliability, and/or cost.

The term "computer readablemedium" as used herein refersto any medium that participates inproviding instructions tothe processor 1203 for execution. A computer readable medium may take many forms, including but not limited to, non-volatilemedia, volatile media, and transmissionmedia. Non-volatilemedia includes,for example, optical, magneticdisks, and magneto-opticaldisks, such as the hard disk 1207 or the removable media drive 1208. Volatile media includes dynamic memory,such as the main memory 1204. Transmissionmedia includes coaxial cables, copperwire and fiber optics,including the wires that make up thdbus 1202. Transmissionmedia may also take the form of acousticor light waves, such as those generated during radio wave and infrared data communications.

The computer system 1201 canalso include a communication interface 1213coupled to the bus 1202. The communication interfacel213 provides a two-waydata communication coupling toa network link 1214 that is connectedto, for example, a local area network (LAN) 1215, or to another communications networkl216 such as thelnternet. Forexample, the communication interfaced 13 may be a networkinterface cardto attach to any packet switched LAN. As another example,the communicationinterface 1213 maybe an asymmetrical digital subscriber line (ADSL) card, arintegrated servicesdigital network (ISDN)card or a modem to provide a data communicationconnectionto a corresponding type ofcommunications line. Wireless linksmay also be implemented. Inany such implementation, the communication interface 1213 sendsand receives electrical, electromagnetic or optical signals thatarry digital data streams representing varioustypes of information.

The network link 1214 typically providesdata communicationthrough one or more networks to other datadevices. Forexample, the network link 1214 may provide aconnection to another computerthrough a local network 1215 (e.g., a LAN) or through equipment operated by a service provider, which providesommunication services througba communications network 1216. In one embodiment, this capability permitthe invention to have multipleof the above described controllers 500 networked together for purposes such as factoiywide automation or quality control. The local network 1215 and the communicationsnetwork 1216 use, for example, electrical, electromagnetic, or optical signals thatcarry digital data streams, and the associatedphysical layer (e.g., CAT 5 cable, coaxiabable, optical fiber, etc). The signals through the various networks andthe signals on the network link 1214 andthrough the communication interfaced 13, which carry the digital data to andfrom the computer system 1201 may be implementedin baseband signals, or carrier wavebased signals. Thebaseband signals convey the digital data as unmodulated electrical pulses thafere descriptiveof a stream of digital data bits, where the terrri'bits" is to be construed broadly tcmean symbol, where each symbol conveys at leastone or more information bits. The digital data may also be used to modulate a carrier wave, such as with amplitude, phase and/or frequency shift keyed signalfchat are propagated overa conductive media, or transmitted aselectromagneticwaves througha propagation medium. Thus, the digitaldata may be sent as unmodulatedbasebanddata through a "wired" communicationchannel and/or sent withina predeterminedfrequencyband, different than baseband, bymodulating a carrier wave. The computer system 1201 can transmitand receive data, includingprogram code, through the network(s) 1215and 1216, the network link 1214, and the communicationinterface 1213. Moreover, the networklink 1214 may provide a connection through a LAN 1215 to a mobile device 1217 such as a personal digital assistant (PDA) laptop computer,or cellulartelephone.

More specifically, in one embodiment of the invention, a continuous castingnd rolling system (CCRS) is provided which can produce pure electrical conductor gradealuminum rod and alloy conductor grade aluminum rod coilsdirectly from moltenmetal on a continuous basis. The CCRS can use one or moreof the computer systems 1201(described above) to implement control, monitoring, and data storage.

In one embodiment ofthe invention, to promoteyield of a high quality aluminumrod, an advanced computer monitoring and data acquisition (SCADA)system monitors and/orcontrols the rolling mill (i.e., the CCRS). Additional variables andparameters ofthis system canbe displayed, charted, stored and analyzed for quality control.

In one embodiment ofihe invention, one oimore of the followingpost production testing processesare captured in the data acquisition system.

Eddy current flawdetectors can be used in line to continuously monitor thesurface quality of the aluminum rod. Inclusions, if located near the surface of the rod, can be detected since the matrix inclusion acts as a discontinuousdefect. During the casting and rolling of aluminum rod, defects inthe finished productcan comefrom anywhere in theprocess. Incorrect melt chemistry and/or excessive hydrogen in the metal can cause flaws during the rolling process. The eddy current system is a non-destructive test, and the control system for the CCRS can alert the operator(s) to any one of the defects described above. The eddy current system can detect surface defects, and classify the defects as small, medium or large. The eddy current results can be recorded in the SCADA system andtracked to the lot of aluminum (or otheimetal being processed) and whenit was produced.

Once the rod is coiled at theend of the process the bulk mechanical anelectrical propertiesof castaluminum can be measuredand recorded in the SCADAsystem. Product quality tests include: tensile, elongation, and conductivity. The tensile strengthis a measure of the strength of the materials and is the maximum force thematerial can withstand undertension before breaking. The elongationvalues are a measure of the ductility of the material.

Conductivity measurementsare generally reported asa percentage of the "international annealed copper standard" (IACS). These product quality metrics canbe recorded in theSCADA system and tracked to the lot of aluminum and whenit was produced.

In addition to eddy current data, surface analysis canbe carried out usingtwist tests. The cast aluminum rod is subjected to a controlled torsiontest. Defects associated with improper solidification, inclusions and longitudinal defects created during the rolling processare magnified and revealed on the twisted rod. Generally, these defectsnanifest in theform of a seam that is parallel to the rollingthe direction. A series of parallel lines after the rod is twisted clockwiseand counterclockwiseindicates that the sampleis homogeneous,while non- homogeneitiesin the casting process will resultin fluctuating lines. The results of the twisttests can be recorded in the SCADA system and tracked to the lot of aluminum and when itwas produced.

Sample Analysis

The samples discussedbelowwere made with the CCR system noted above. The casting and rolling process which produced the samples started as a continuous stream of molten aluminum from a system of melting and holding furnaces, delivered through a refractory lined launder system to either an in-line chemical grain refining system or the ultrasonic grain refinement system discussed above. Additionally, the CCR system included the ultrasonic degassing system discussedabove which uses ultrasonic acoustic waves and a purge gas in order to remove dissolvedhydrogen or other gases from the molten aluminum. From the degasser, the metal flowed to a molten metal filter with porous ceramic elements which further reduce inclusions in the molten metal. The launder system then transports the molten aluminum to the tundish. From the tundish, the molten aluminum was poured into a mold formed by the peripheral groove of a copper casting ring and a steel band, as discussed above. Molten aluminum was cooled to a solid cast bar by water distributed through spray nozzles from multi- zone water manifolds with magnetic flow meters for critical zones. The continuous aluminum cast bar exited thecasting ring onto a bar extraction conveyor to a rolling mill.

The rolling mill included individually driven rolling stands that reduce the diameter of the bar. The rod was then sent to a drawing mill where the rods were drawn to predetermined diameters, and then coiled. Once the rod was coiled at the end of the process the bulk mechanical and electrical properties of cast aluminum were measured. The quality tests include: tensile, elongation, and conductivity. The Tensile strength is a measure of the strength of the materials and is the maximum force the material can withstand under tension before breaking. The elongation values are a measure of the ductility of the material. Conductivity measurements are generally reported as a percentage of the "international annealed coppeartandard" (IACS). )

1) The Tensile strength isa measure of the strengthof the materials andis the maximum force the material can withstand undertension before breaking. The tensile and elongation measurements werecarried out on the same sample. A 10" gage length sample was selectedfor tensileand elongation measurements. The rod sample was inserted into thetensile machine. The grips were placedat 10" gauge marks. Tensile Strength = Breaking Force

2

(pounds)/Cross sectional area (" ^r ) where r(inches) is the radius of the rod.

2) % Elongation = ((Z ₇ - L ₂ )/ Li)X100. Lj is the initial gagelength of the material and L ₂ is the final length that is obtained by placing the two broken samplesfrom the tension test together and measuring thefailure that occurs. Generally, themore ductile the material themore neck down will be observedin the sample in tension.

3) Conductivity: Conductivity measurementare generally reported as a percentage^ the "international annealed copper standard" (IACS). Conductivity measurementsare carried out using Kelvin Bridge and detail s are provided in ASTM B 193 -02. IACS is a unit of electrical conductivity formetals and alloys relative to a standard annealed copper conductor; aSACS value of 100% refers to a conductivity of5.80 x 107 siemensper meter (58.0 MS/m) at 20 °C

The continuous rod process as described above was used to produce not only electrical grade aluminum conductors, but also can be used for mechanical aluminum alloys utilizing the ultrasonic grain refining and ultrasonic degassing. For testing the ultrasonic grain refining process, cast bar samples were collected and etched.

A comparative analysis was completed on the rod propertiesbetween a rod that was cast using ultrasonic grain refining process and a rod cast using conventional TIBOR grain refiners.

Table 1 shows the results of rod processed using the ultrasonic grain refiner vs. results of rod processedusing TIBOR grain refiners. Table 1 : Quality Tests: ultrasonicgrain refining vs. chemicalgrain refining ¹

Defects associated with improper solidification, inclusions and longitudinal defects created during the rolling process were magnified and revealed on the twisted rod. Generally these defects manifest in the form of a seam that is parallel to the rolling the direction. A series of parallel lines after the rod is twisted clockwise and counterclockwiseindicatesthat the sample is homogeneous whilenon-homogeneitiesin the casting process wilkesult in fluctuatinglines.

The data in Table 2 below indicated that very few flaws were producedusing ultrasonics.

While no definitive conclusionshave been reached, at least from this set of data points, it appears that the number of surface defects observed by an eddy current tester was lower for the material processed using ultrasonics.

Table 2: Flaw Analysis: ultrasonic grain refining vs. chemicagrain refining

¹ a: 1000 lbs. per sq. in ; b: Percentage of Elongation; c: Reported as% IACS; d: Averageof 13 rod coils The twist test results indicated that the surface quality of the ultrasonic grain refined rod was as good as the surface quality of rod produced using chemical grain refiners. After the ultrasonic grain refiner was installed on the continuous rod (CR) process, the chemical grain refiner was reduced to zero while producing high quality cast bar. The hot rolled rod was then drawn down to various wire sizes ranging from 0.1052" to 0.1878". The wires were then processed intooverhead transmission cables.

There are two separate conductors that the product could be used for: aluminum conductor steel supported (ACSS) or aluminum conductor steel reinforced (ACSR). One differencebetweenthe two processes of making the conductors is that the ACSS aluminum wire is annealed after stranding.

Figure 10 is an ACSR wire processflow diagram. It shows the conversion ofpure molten aluminum into aluminum wirethat will be used in ACSR wire. The firststep in the conversionprocess is to convertible molten aluminum into aluminum rod. In the next stepthe rod is drawn throughseveral dies anddepending onthe end diameter this may be accomplished through oneor multiple draws. Oncethe rod is drawn to final diameters the wire is spooled onto reels of weights rangingbetween 200 and 500 lbs. These individual reelsare stranded around a steel stranded cable intoACSR cablesthat contains several individual aluminum strands. The number of strands and the diameter of each strand will dependon the customer requirements.

Figure 11 is an ACSS wire process flowdiagram. It shows theconversion ofpure molten aluminum into aluminum wirethat will be used in ACSS wire. The firststep in the conversionprocess is to processthe molten aluminuminto aluminum rod. In the next step, the rod is drawn throughseveral dies anddepending onthe end diameter this may be accomplished through oneor multiple draws. Oncethe rod is drawn to final diameters the wire is spooled onto reels of weights ranging^etween 200 and 500 lbs. These individual reelsare stranded around a steel stranded cable intoACSS cablesthat contains several individual aluminum strands. The number of strands and the diameter of each strand will dependon the customer requirements. One difference between the ACSR¾nd ACSS cable is that, oncethe aluminum isstranded around the steel cable, thewhole cable is heattreated in furnaces to bringthe aluminum to a dead soft condition. It is important tonote that in ACSR the strength of the cable is derived from the combinationof the strengthsdue to the aluminumand steel cable while inthe ACSS cable most of the strength comesfrom the steel insidethe ACSS cable.

Figure 12 is an aluminum strip process flowdiagram, where thestrip is finally processed into metal clad cable. It showsthat the first step is to convert the molten aluminuminto aluminum rod. Following this the rod is rolled throughseveral rolling diesto convert itinto strip, generally of aboutO.375" in width and aboutO.015 to 0.018" thickness. The rolled strip is processed intodonut shapedpads thatweigh approximately 600 lbs. It is importantto note that other widthsand thicknesses can alsobe produced usingthe rolling process, but the 0.375"width and 0.015 to 0.018" thickness are themost common. These padsare then heat treated in furnaces to bringthe padsto an intermediate annealcondition. In this condition, thealuminum is neither fully hard or in a dead soft condition. The strip is then used as a protectivjeacket assembled as an armor of interlocking metal tape(strip) that encloses one or moreinsulated circuit conductors.

The comparative analysis shown belowbased on these processes was completedn aluminum drawn wire that was processedwith the ultrasonic grain refining procesand aluminum wire that was processed using conventional TIBOR grain refiners. Afejpecifications as outlinedin the ASTM standards forl350 electrical conductor wirewere met on the drawn samples. Properties of Conventional Rod Includinfi TIBOR chemical firain refiners

5356 * Rod .375" Diame ter Tensile* KSI Tensile ¹³ Mpa Elongation' IACS% ^D

AVE RAG

E 43.97 302.9533 18.5 N/A

STD Dev 0.613269924 4.225429778 0.5 N/A

Min 43.4 299.026 18 N/A

Max 45.2 311.428 19 N/A

Properties-of Ultrasonic Processed Rod

PROCESSING CONDITIONS FOR ULTRASONIC PROCESSED RODS

5

* Alloy designations are per Aluminum Association Specifications

** Aluminum Conductor Steel Supported

*** Aluminum Conductor Steel Reinforced

A. 1000 lbs. per square inch

B. Tensile strength in mega pascals

C. Percentage Elongation

D. International Annealed Copper Standard

* All length dimensions are in inches.

Figure 15 is a micrographiccomparison of analuminum 1350 EC alloy showing the grain structure of castings with no chemical grain refiners,with grain refiners, andwith only ultrasonic grain refining.

10 Figure 16 is tabular comparison of a conventionall 350 EC aluminum alloy rod(with chemical grain refiners)to a 1350 EC aluminum alloy rod (with ultrasonic grain refinement).

Figure 17 is tabular comparison of a conventionalACSR aluminum Wire 0.130" Diameter (with chemical grain refiners)to ACSR aluminum Wire 0.130" Diameter (with ultrasonic grain refinement).

15 Figure 18 is tabular comparison of a conventionaB 176 EEE aluminum alloy rod (with chemical grain refiners)to an 8176 EEE aluminum alloy rod (with ultrasonic grain refinement).

Figure 19 is tabular comparison of a conventional) 154 aluminum alloy rod (with chemical grain refiners)to a 5154 aluminum alloy rod (with ultrasonic grain refinement). Figure 20 is tabular comparison of a conventional 154 aluminum alloy strip (with chemical grain refiners)to a 5154 aluminum alloy strip(with ultrasonic grain refinement).

Figure 21 is tabular depiction of the properties of a 5356 aluminumalloy rod (with ultrasonic grain refinement).

Generalized Statements of the Invention

The following statements ofthe invention provide one or morecharacterizations ofthe present invention and do not limit the scope of the present invention.

Statement 1. A moltenmetal processingdevicefor a casting wheel on a castingmill, comprising: an assembly mounted on (or coupledto) the casting wheel, including at least one vibrational energysource which supplies (e.g., whichhas a configuration which supplies) vibrational energy (e.g., ultrasonic, mechanically-driven, and/oacoustic energy supplied directly or indirectly) tomolten metal cast in the castingwheel while the molten metal in the casting wheel is cooled, a supportdevice holdingthe at least one vibrational energysource, and optionally a guide device whichguides the assembly withrespect to movement of thecasting wheel.

Statement 2. The deviceof statement 1, wherein the support devi concludes a housing comprising acooling channel for transport of a cooling mediumtherethrough. Statement 3. The device of statement2, whereinthe cooling channel includes saidcooling medium comprising at least one of water, gas, liquid metal, and engine oils.

Statement 4. Thedevice ofstatement 1, 2, 3, or 4. wherein the atleast one vibrational energy source comprises at least one ultrasonictransducer, at least one mechanically-driven vibrator, or a combination thereof.

Statement 5. Thedevice ofstatement 4, wherein the ultrasonic transducei(e.g., a piezoelectric elements configuredto provide vibrational energy in a rangeof frequencies up to 400 kHz or whereinthe ultrasonic transducer (e.g., a magnetostrictive elements configured to provide vibrational energy ina range offrequencies 20to 200 kHz. Statement 6. The device of statement 1, 2, or 3, whereinthe mechanically-drivenvibrator comprises a plurality of mechanically-drivenvibrators. Statement?. The deviceof statement 4, whereinthe

mechanically-drivenvibrator is configuredto provide vibrational energyin a range of frequencies upto 10 KHz, or whereinthe mechanically-driven vibrator isconfigured to provide vibrational energyin a range of frequenciesfrom 8,000 to 15,000 vibrations per minute.

Statement 8a. Thedevice of statement 1, wherein the casting wheelncludes a band confiningthe moltenmetal in a channel of the casting wheel. Statement 8b. The device of any one of statements 1-7, w herein the assembly ispositioned above thecasting wheeland has passages in ahousing for a band confining the moltermetal in the channel ofthe casting wheel to pass therethrough. Statement 9. The devicef statements, wherein said band is guided along the housing topermit the cooling mediumfrom the cooling channelto flow alonga side of the band opposite the moltenmetal.

Statement 10. The deviceof any one ofstatements l-9, whereinthe supportdevice comprisesat least one or more of niobium, a niobium alloy, titanium, a titanium alloy, tantalum, a tantalum alloy, copper, a copper alloy, rhenium, a rheniumalloy, steel, molybdenum, a molybdenum alloy, stainless steel, a ceramic, a composite, a polymer, or a metal. Statement 11. The device ofstatement 10, wherein the ceramic comprises a silicomitride ceramic. Statement 12. The device of statement 11, wherein the siliconnitride ceramiccomprises a SIALON.

Statement 13. The deviceof any one ofstatements l-12, wherein thehousing comprises a refractory material. Statements. The deviceof statement 13, wherein therefractory material comprisesat least one of copper, niobium, niobiumand molybdenum, tantalum, tungsten, and rhenium, and alloys thereof. Statement 15. The deviceof statement 14, wherein therefractory material comprisesone or more of silicon, oxygen, omitrogen.

Statement 16. The deviceof any one ofstatements 1-15, wherein theat least one vibrational energysource comprises more than onevibrational energy sources in contact with a cooling medium; e.g., in contactwith a cooling medium fiowingthrough the support device or the guide device. Statement 17. The deviceof statement 16, whereinthe at least one vibrational energy source comprisesat least one vibrating probe insertedinto a cooling channel in the support device. Statements. The deviceof any one of statements 1-3 and 6-15, whereinthe at least one vibrational energy source comprisesat least one vibrating probein contact with the support device. Statementl9 The deviceof any one of statements 1-3 and 6-15, whereinthe at least one vibrational energy source comprisesat least one vibrating probein contact with a band at a base of the supportdevice. Statement 20. The deviceof any one of statements 1-19, wherein the at least onevibrational energy source comprisesplural vibrational energy sources distributed at differentpositionsin the support device.

Statement 21. The deviceof any one ofstatements 1-20, wherein theguide deviceis disposed on a band on a rim of the casting wheel.

Statement 22. Amethod for forming a metal product,comprising:

providing moltenmetal into a containment structureof a castingmill;

cooling the molten metalin the containmentstructure, and coupling vibrational energyinto the molten metal in the containment structure during said cooling.

Statement 23. The methodof statement22, wherein providing molten metabomprises pouring molten metal into a channel in a casting wheel.

Statement 24. The methodof statements 22 or 23, wherein coupling vibrational energy comprises supplying said vibrational energyfrom at least one of an ultrasonic transduceor a magnetostrictivetransducer. Statement 25. The method of statement 24, wherein supplyingsaid vibrational energycomprisesprovidingthe vibrational energyin a range of frequenciesfrom 5 and 40 kHz. Statement26. The method of statements 22 or 23, wherein coupling vibrational energy comprisessupplying said vibrational energy from a mechanically-driveivibrator.

Statement27. The method of statement 26, wherein supplyingsaid vibrational energycomprises providing the vibrational energy n a range of frequenciesfrom 8,000 to 15,000 vibrations per minute or up to 10 KHz.

Statement 28. The methodof any one of statements 22-27, wherein cooling comprises cooling the molten metal by application of at least one of water, gas, liquidmetal, and engine oil to a confinementstructure holdingthe moltenmetal.

Statement 29. The methodof any one of statements 22-28, wherein providing molten metal comprises delivering said molten metalinto a mold. Statement 30. The method ofany one of statements 22-29, wherein providing molten metal comprises delivering said molten metainto a continuous casting mold. Statement 31. The method ofany one of statements 22-30, wherein providing molten metal comprisesdelivering saidmolten metal intoa horizontal or vertical casting mold.

Statement 32. Acasting mill comprising a casting mold configured toool molten metal, and the molten metal processing device of any one ofstatements 1-21. Statement 33. Themill of statement32, wherein the moldcomprises a continuous casting mold. Statements. The mill of statements32 or 33, wherein the mold comprisesa horizontal or vertical castingmold.

Statement 35. A casting mill comprising: a molten metal containment structure configured to cool molten metal; and a vibrational energysource attached to the moltenmetal containment and configured to couple vibrational energy into the moltenmetal at frequencies ranging up to 400 kHz.

Statement 36. Acasting mill comprising:a molten metal containment structure configured to cool molten metal; and a mechanically-driven vibrationabnergy source attached to the molten metal containment and configuredto couple vibrational energy atfrequencies ranging up to 10 KHz (including a range from 0 tol 5,000 vibrations per minute and 8,000 to

15,000 vibrations per minute) into the molten metal.

Statement 37. Asystem for forminga metal product, comprising: means forpouring moltenmetal into a molten metal containment structure; means for cooling them ol ten metal containment structure; means for coupling vibration energy intcthe moltenmetal at frequencies ranging up to 400 KHz (includingranges from 0 to 15,000 vibrations per minute, 8,000 to

15,000 vibrations per minute, up to 10 KHz, 15 to 40 KHz, or 20 to 200 kHz); and a controller including data inputs and control outputs, and programmed with controklgorithms whichpermit operation of any one of the step elements recited in statements22-31.

Statement 38. Asystem for forminga metal product, comprising: themolten metal processingdevice of any one of the statements 1-21; and a controller including data inputs and control outputs, and programmed with control algorithms which permit operatiorof any one of the step elements recited in statements 22-31.

Statement 39. A system forforming a metal product,comprising: an assembly coupled to the casting wheel, including a housing holdinga cooling medium such thatmolten metal cast in the casting wheel is cooled by the cooling mediumand a device which guides the assembly with respect to movement of the casting wheel.

Statement 40. The system of statement 8 including any of the elements defined in statements 2-3, 8-15, and 21.

Statement 41. Amolten metal processingdevice for a castingmill, comprising: at least one vibrational energy sourcewhich suppliesvibrational energy into moltenmetal castin the casting wheel while the moltenmetal in the casting wheel is cooled; and a support device holding said vibrational energy source.

Statement 42. The device of statement 41including any of the elements defmedn statements 4-15.

Statement 43. A moltenmetal processingdevice for a casting wheel on a castingmill, comprising: an assembly coupled to the castingwheel, including l)at least one vibrational energy sourcewhich suppliesvibrational energy to molten metal cast in the casting wheel while the molten metal in the casting wheel is cooled, 2) a support device holdingsaid at least one vibrational energy source, and 3) an optional guide device which guides theassembly with respectto movementof the castingwheel.

Statement 44. The device of statement 43, whereirthe at least one vibrational energy source supplies the vibrational energy directly into the molten metabast in the castingwheel. Statement 45. The device of statement 43, whereirthe at least one vibrational energy source supplies the vibrational energy indirectly into themolten metal cast in the castingwheel.

Statement 46. A moltenmetal processingdevicefor a casting mill, comprising: at least one vibrational energy sourcewhich suppliesvibrational energy by a probe insertednto molten metal cast in the casting wheel while the moltenmetal in the casting wheel is cooled; anck support device holding said vibrational energy source, whereirthe vibrational energy reduces moltenmetal segregation asthe metal solidifies.

Statement 47. The device of statement 46, includingany of the elements defined in statements 2-21.

Statement 48. A molten metal processingdevicefor a castingmill, comprising: at least one vibrational energy sourcewhich suppliesacoustic energy into moltenmetal cast in the casting wheel while the moltenmetal in the casting wheel is cooled; and a support device holding said vibrational energy source.

Statement 49. The deviceof statement48, wherein theat least one vibrationalenergy source comprisesan audio amplifier.

Statement 50. The device of statement 49, whereirthe audio amplifiercouples vibrational energythrough a gaseous mediuminto the molten metal.

Statement 51. The device of statement 49, whereirthe audio amplifiercouples vibrational energythrough a gaseous mediuminto a support structure holding themolten metal.

Statement 52. A methodfor refining grain size,comprising: supplying vibrational energy to a moltenmetal while the moltenmetal is cooled; breakingapart dendrites formed in the molten metal to generate a source of nuclei inthe molten metal.

Statement 53. The method ofstatement 52, wherein the vibrationalenergy comprises at least one or more of ultrasonic vibrations, mechanically-driven vibrations, ancacoustic vibrations.

Statement 54. The method ofstatement 52, wherein the source ofiuclei in the molten metal does not include foreign impurities.

Statement 55. The method ofstatement 52, wherein a portion of the moltenmetal is undercooledto produce saiddendrites.

Statement 56. A molten metal processingdevice comprising:

a source of molten metal;

an ultrasonic degasserincluding an ultrasonicprobe inserted into the moltermetal; a casting for reception ofthe moltenmetal;

an assemblymounted on the casting, including, at least one vibrational energy source which suppliesvibrational energyto molten metal cast in the casting while the molten metal in the casting-is cooled, and

a support device holdingsaid at least one vibrational energy source.

Statement 57. The device of statement 56, whereirthe casting comprises a component of a casting wheel of a casting mill.

Statement 58. The device of statement 56, whereirthe supportdevice includes a housing comprising acooling channel for transport of a cooling mediumtherethrough.

Statement 59. The device of statement 58, whereirthe cooling channelincludes said coolingmedium comprisingat least one of water,gas, liquidmetal, and engine oils.

Statement 60. The device of statement 56, whereirthe at least one vibrational energy source comprisesan ultrasonic transducer.

Statement 61. The device of statement 56, whereirthe at least one vibrational energy source comprisesa mechanically-drivenvibrator.

Statement 62. The device of statement 61, whereirthe mechanically-drivenvibrator is configured to provide vibrational energy in a range of frequenciesfrom up to 10 KHz.

Statement 63. The device of statement 56, whereirthe casting includes a band confining the molten metal in a channel of a casting wheel.

Statement 64. The device of statement 63, whereirthe assembly is positionedabove the casting wheel and has passagesin a housing fora band confiningthe moltenmetal in a channel of the casting wheel to pass therethrough.

Statement 65. The device of statement 64, whereinsaid band is guided alongthe housing to permit the coolingmedium from the cooling channel to flowalong a side of the band opposite the moltenmetal.

Statement 66. The device of statement 56, whereirthe supportdevice comprisesat least one or more of niobium, a niobium alloy, titanium, a titanium alloy, tantalum, a tantalum alloy, copper, a copper alloy, rhenium, a rhenium alloy, steel, molybdenum, a molybdenum alloy, stainless steel, a ceramic, a composite, a polymer, or a metal.

Statement 67. The device of statement 66, whereirthe ceramic comprises a silicon nitride ceramic.

Statement 68. The device of statement 67, whereirthe silicon nitride ceramic comprises a SIALON.

Statement 69. The device of statement 64, whereirthe housing comprises a refractory material. Statement 70. The device of statement 69, whereiithe refractory material comprisesat least one of copper, niobium, niobium and molybdenum, tantalum, tungsten, ancrhenium, and alloys thereof.

Statement 71. The device of statement 69, whereiithe refractory material comprisesone or more of silicon, oxygen, or nitrogen.

Statement 72. The device of statement 56, whereiithe at least one vibrational energy source comprisesmore than one vibrational energy sources in contactwith a cooling medium.

Statement 73. The device of statement 72, whereiithe at least one vibrational energy source comprisesat least one vibrating probeinserted intoa cooling channel in the support device.

Statement 74. The deviceof statement 56, whereinthe at least one vibrational energy source comprisesat least one vibrating probein contactwith the support device.

Statement 75. The deviceof statement 56, whereinthe at least one vibrational energy source comprisesat least one vibrating probein direct contactwith a band at a base of the support device.

Statement 76. The deviceof statement 56, whereinthe at least one vibrational energy source comprisesplural vibrational energy sources distributed atiifferentpositionsin the support device.

Statement 77. The device of statement 57, further comprising a guiddevice which guides the assembly with respectto movementof the casting wheel.

Statement 78. The device of statement 72, whereiithe guide device is disposed on a band on a rim of the casting wheel.

Statement 79. The deviceof statement 56, whereinthe ultrasonic degasser comprises: an elongated probe comprising a first endand a second end, the first end attachedto the ultrasonic transducer and the second end comprising a tip, and

a purging gas delivery comprising a purging gas inl eland a purging gas outlet, said purging gas outlet disposedat the tip of the elongated probe for introducing a purginggas into the molten metal.

Statement 80. The deviceof statement 56, whereinthe elongated probe comprisesa ceramic.

Statement 81. A metallic productcomprising:

a cast metallic composition havingsub-millimeter grain sizes andncluding less than 0.5% grain refinerstherein and having at least oneof the following properties:

an elongation which rangesfrom 10 to30% under a stretching force of 100 lbs/iif, a tensile strength which ranges from 5Qo 300 MPa; or

an electrical conductivity whicrranges from 45 to 75% of IAC, where IAC is a percent unit of electrical conductivity relative to a standard annealed copper conductor.

Statement 82. The product of statement 81, wherein thecomposition includes less than 0.2% grain refinerstherein.

Statement 83. The productof statement 81, whereinthe composition includes leslhan 0.1% grain refinerstherein.

Statement 84. The productof statement 81, whereinthe composition includes no grain refinerstherein.

Statement 85. The productof statement 81, whereinthe composition includes aieast one of aluminum, copper, magnesium, zinc,lead, gold, silver, tin, bronze,brass, and alloys thereof.

Statement 86. The productof statement 81, whereinthe composition is formed into at least one of a bar stock, a rod, stock, a sheet stock, wires, billets, an<f)ellets.

Statement 87. The product ofstatement 81, wherein theelongati on ranges from 15 to

25%), or the tensile strength ranges from 100 to 200 MPa, or the electrical conductivity which ranges from 50 to 70% of IAC.

Statement 88. The product ofstatement 81, wherein theelongati on ranges from 17 to 20%), or the tensile strength ranges from 150 to 175 MPa, or the electrical conductivity which ranges from 55 to 65% of IAC.

Statement 89. The product ofstatement 81, wherein theelongati on ranges from 18 to 19%), or the tensile strength ranges from 160 to 165 MPa, or the electrical conductivity which ranges from 60 to 62% of IAC.

Statement 90. The product of any one ofstatements 81, 87, 88, and89, whereinthe compositioncomprises aluminum or an aluminum alloy.

Statement 91. The product of statement 90, wherein thealuminum or the aluminum alloy comprisesa steel reinforced wire strand.

Statement 92. The product ofstatement 90, wherein thealuminum or thealuminum alloy comprisesa steel supported wire strand.

Statement 92. A metallic productmade by any one or more of the processsteps set forth in statements 52-55, and comprising a cast metalliccomposition.

Statement 93. The product ofstatement 92, wherein thecast metallic composition has sub-millimetergrain sizes and includes lessthan 0.5% grain refiners therein. Statement 94. The product of statement 92, wherein themetallic producthas at least one of the followingproperties:

an elongation which rangesfrom 10 to30% under a stretching force of 100 lbs/ir?, a tensile strength which ranges from 5 ⁽ k> 300 MPa; or

5 an electrical conductivity whicrranges from 45 to 75% of IAC, where IAC is a percent unit of electrical conductivity relative to a standard annealed copper conductor.

Statement 95. The product of statement 92, wherein thecomposition includes less than 0.2% grain refinerstherein.

Statement 96. The productof statement 92, whereinthe composition includes leslhan 10 0.1% grain refinerstherein.

Statement 97. The productof statement 92, whereinthe composition includes no grain refinerstherein.

Statement 98. The productof statement 92, whereinthe composition includes aieast one of aluminum, copper, magnesium, zinc,lead, gold, silver, tin, bronze,brass, and alloys 15 thereof.

Statement 99. The productof statement 92, whereinthe composition is formed into at least one of a bar stock, a rod, stock, a sheet stock, wires, billets, and ellets.

Statement 100. The product of statements, wherein theelongati on ranges from 15 to 25%), or the tensile strength ranges from 100 to 200 MPa, or the electrical conductivity which 20 ranges from 50 to 70% of IAC.

Statement 101. The product of statements, wherein theelongati on ranges from 17 to 20%), or the tensile strength ranges from 150 to 175 MPa, or the electrical conductivity which ranges from 55 to 65% of IAC.

Statementl02. The productof statement 92, whereinthe elongation ranges from 18 to 25 19%), or the tensile strength ranges from 160 to 165 MPa, or the electrical conductivity which ranges from 60 to 62% of IAC.

Statement 103. The product of statements, wherein thecomposition comprises aluminum or an aluminum alloy.

Statement 104. The product of statement! 03, wherein the aluminumor the aluminum 30 alloy comprisesa steel reinforcedwire strand.

Statement 105. The product of statement! 03, wherein the aluminumor the aluminum alloy comprisesa steel supported wire strand. Numerous modificationsand variations of the present invention are possible in light of the above teachings. lt is thereforeto be understood thatwithin the scope of theappended claims, the invention may be practiced otherwise thanas specifically described herein.