BACKGROUND

[001] Aluminum alloys are useful in a variety of applications. However, improving one property of an aluminum alloy without degrading another property often proves elusive. For example, it is difficult to increase the strength of an alloy without decreasing the toughness of an alloy. Other properties of interest for aluminum alloys include thermal stability, corrosion resistance and fatigue crack growth rate resistance, to name two.

FIELD OF THE INVENTION

[002] The field of the invention relates to aluminum alloy products and methods for making the same.

SUMMARY OF THE INVENTION

[003] Broadly, the present patent application relates to new aluminum alloys. Generally, the new aluminum alloys comprise (and some instances consist essentially of or consist of) from 1.2 to 4.1 at. % Fe, from 0.2 to 1.1 at. % of Class X elements, where the at. % Fe plus at. % Class X elements (i.e., (at. % Fe) + (at. % Class X elements)) is from 2.3 to 4.3 at. %, and from 0.9 to 2.5 at. % Si. The Class X elements generally comprise at least one of vanadium (V), molybdenum (Mo), niobium (Nb), tantalum (Ta), and tungsten (W). Furthermore, the new aluminum alloys generally include an amount of the Fe, the Class X elements, and the Si falling within an area on a graph having (at. % Fe plus at. % Class X) content on one axis and having (at. % Si) on another axis, the area being defined by the following comers in Table 1, below.

Table 1: Corners Defining the Amount of (Fe + X) + Si

in the New Aluminum Alloys

FIG. 1 is a graph of at. % Si versus at. % (Fe + X) that illustrates the aluminum alloy composition space for the new aluminum alloys described herein. The use of iron (or its transition metal substitutes, noted below) the Class X elements, and the silicon may facilitate, for instance, the formation of a-AlFeSi phase while restricting the formation of Ak,(Fe,Mn) phases in the alloy. The a-AlFeSi phase may facilitate, for instance, improved thermal stability. Restriction of Ak,(Fe,Mn) phases may facilitate, for instance, production of crack- free products. In some embodiments, the balance of the new aluminum alloys is aluminum, optional incidental elements, and impurities. Products incorporating such alloy compositions may achieve an improved combination of, for instance, printability in additive manufacturing, strength, and/or ductility, among others.

BRIEF DESCRIPTION OF THE DRAWINGS

[004] FIG. 1 is a graph showing the boundaries of (Fe + X) and Silicon for the new aluminum alloys described herein.

DETAILED DESCRIPTION

i. Composition

[005] As noted above, the new aluminum alloys generally include from 0.9 to 2.5 at. % Si. In one embodiment, a new aluminum alloy includes at least 1.0 at. % Si. In another embodiment, a new aluminum alloy includes at least 1.1 at. % Si. In yet another embodiment, a new aluminum alloy includes at least 1.2 at. % Si. In another embodiment, a new aluminum alloy includes at least 1.3 at. % Si. In one embodiment, a new aluminum alloy includes not greater than 2.4 at. % Si. In another embodiment, a new aluminum alloy includes not greater than 2.4 at. % Si. In yet another embodiment, a new aluminum alloy includes not greater than 2.3 at. % Si. In another embodiment, a new aluminum alloy includes not greater than 2.1 at. % Si. In yet another embodiment, a new aluminum alloy includes not greater than 2.0 at. % Si.

[006] As noted above, the new aluminum alloys generally include an amount of Fe plus Class X elements (i.e., (at. % Fe) + (at. % Class X elements)) of from 2.3 to 4.3 at. %. In one embodiment, the amount of at. % Fe plus at. % Class X elements in a new aluminum alloy is not greater than 4.2 at. %. In another embodiment, the amount of at. % Fe plus at. % Class X elements in a new aluminum alloy is not greater than 4.1 at. %. In yet another embodiment, the amount of at. % Fe plus at. % Class X elements in a new aluminum alloy is not greater than 4.0 at. %. In another embodiment, the amount of at. % Fe plus at. % Class X elements in a new aluminum alloy is not greater than 3.95 at. %. In another embodiment, the amount of at. % Fe plus at. % Class X elements in a new aluminum alloy is not greater than 3.9 at. %. In yet another embodiment, the amount of at. % Fe plus at. % Class X elements in a new aluminum alloy is not greater than 3.85 at. %. In another embodiment, the amount of at. % Fe plus at. % Class X elements in a new aluminum alloy is not greater than 3.8 at. %. In yet another embodiment, the amount of at. % Fe plus at. % Class X elements in a new aluminum alloy is not greater than 3.75 at. %.

[007] In some embodiments, the new aluminum alloys comprise up to 4.0 at. % of Class Z elements. The Class Z elements are generally comprised of at least one of copper (Cu), magnesium (Mg), zinc (Zn), lithium (Li), and silver (Ag). In one embodiment, a new aluminum alloy includes from 0.01 to 4.0 at. % of Class Z elements. In one embodiment, a new aluminum alloy includes up to 3.0 at. % of Class Z elements. In another embodiment, a new aluminum alloy includes up to 2.0 at. % of Class Z elements. In yet another embodiment, a new aluminum alloy includes up to 1.0 at. % of Class Z elements. In another embodiment, a new aluminum alloy includes up to 0.5 at. % of Class Z elements. In yet another embodiment, a new aluminum alloy includes up to 0.25 at. % of Class Z elements. In another embodiment, a new aluminum alloy includes up to 0.1 at. % of Class Z elements. In yet another embodiment, a new aluminum alloy includes up to 0.05 at. % of Class Z elements. In another embodiment, a new aluminum alloy includes not greater than 0.01 at. % of Class Z elements. In yet another embodiment, a new aluminum alloy includes not greater than 0.005 at. % of Class Z elements.

[008] In some embodiments, the new aluminum alloys comprise up to 3.0 at. % of Class H elements. The Class H elements are generally comprised of at least one of titanium (Ti), zirconium (Zr), and hafnium (Hf). The Class H metals be used for grain refining / grain structure control, for instance. As a non-limiting example, a new aluminum alloy may include titanium, and the titanium may form the intermetallic AhTi phase during solidification (e.g., before the formation of other solid phases). The AhTi that forms during solidification may facilitate alloy crystal formation (i.e., may grain refine). In one embodiment, a new aluminum alloy includes from 0.01 to 3.0 at. % of Class H elements. In one embodiment, a new aluminum alloy includes up to 2.0 at. % of Class H elements. In another embodiment, a new aluminum alloy includes up to 1.0 at. % of Class H elements. In yet another embodiment, a new aluminum alloy includes up to 0.5 at. % of Class H elements. [009] In some embodiments, the new aluminum alloys comprise up to 1.0 at. % of Class

E metals. The Class E metals are generally comprised of at least one of indium (In), tin (Sn), bismuth (Bi), and lead (Pb). In one embodiment, a new aluminum alloy includes from 0.01 to 1.0 at. % Class E metals. In one embodiment, a new aluminum alloy includes up to 0.75 at. % Class E metals. In another embodiment, a new aluminum alloy includes up to 0.50 at. % Class E metals. In yet another embodiment, a new aluminum alloy includes up to 0.25 at. % Class E metals. In another embodiment, a new aluminum alloy includes up to 0.10 at. % Class E metals. In yet another embodiment, a new aluminum alloy includes up to 0.05 at. % Class E metals. In another embodiment, a new aluminum alloy includes not greater than 0.01 at. % Class E metals. In yet another embodiment, a new aluminum alloy includes not greater than 0.005 at. % Class E metals.

[0010] In some embodiments, the new aluminum alloys include up to 2.0 at. % of rare earth elements. In one embodiment, a new aluminum alloy includes up to 1.5 at. % of rare earth elements. In another embodiment, a new aluminum alloy includes up to 1.0 at. % of rare earth elements. In yet another embodiment, a new aluminum alloy includes up to 0.75 at. % of rare earth elements. In another embodiment, a new aluminum alloy includes up to 0.5 at. % of rare earth elements. In yet another embodiment, a new aluminum alloy includes up to 0.25 at. % of rare earth elements. In another embodiment, a new aluminum alloy includes up to 0.1 at. % of rare earth elements. In yet another embodiment, a new aluminum alloy includes up to 0.05 at. % of rare earth elements. In another embodiment, a new aluminum alloy includes not greater than 0.01 at. % of rare earth elements. In yet another embodiment, a new aluminum alloy includes not greater than 0.005 at. % of rare earth elements.

[0011] As used herein,“rare earth elements” includes one or more of, for instance, scandium, yttrium, and any of the fifteen lanthanides elements. The lanthanides are the fifteen metallic chemical elements with atomic numbers 57 through 71, from lanthanum through lutetium.

[0012] As noted above, the balance of the new aluminum alloys may be aluminum and any optional incidental elements and impurities. As used herein,“incidental elements” means those elements or materials, other than the above listed elements, that may optionally be added to the alloy to assist in the production of the alloy. Examples of incidental elements include casting aids, such as grain refiners and deoxidizers. Optional incidental elements may be included in the alloy in a cumulative amount of up to 1.0 at. %. Some incidental elements may be added to the alloy to reduce or restrict (and is some instances eliminate) cracking in the additively manufactured part due to, for example, folds (e.g., oxide folds), pits and patches (e.g., oxide patches). These types of incidental elements are generally referred to herein as deoxidizers. Examples of some deoxidizers include Ca, Sr, P and Be. When calcium (Ca) is included in the alloy, it is generally present in an amount of up to 0.3 wt. %, or up to 0.2 wt. %, or up to 0.1 wt. %. In some embodiments, Ca is included in the alloy in an amount of 0.001-0.1 wt. % or 0.001- 0.2 wt. % or 0.001-0.3 wt. %, such as 0.001-0.25 wt. % (or 10 to 2500 ppm). Strontium (Sr) may be included in the alloy as a substitute for Ca (in whole or in part), and thus may be included in the alloy in the same or similar amounts as Ca. Phosphorus (P) may be included in the alloy as a substitute for Ca or Sr (in whole or in part), and thus may be included in the alloy in the same or similar amounts as Ca or Sr. Traditionally, beryllium (Be) additions have helped to reduce the tendency of cracking in aluminum alloys, though for environmental, health and safety reasons, some embodiments of the alloy are substantially Be-free. When Be is included in the alloy, it is generally present in an amount of up to 0.05 wt. % (e.g., from 10 ppm to 500 ppm of Be). Other incidental elements include carbon and boron, which may be used, for instance, with titanium, to facilitate grain refining, among other things (e.g., when in the form of T1B2 or TiC, for instance). Carbon and/or boron may be included, for instance, in an amount of up to 3.0 wt. %. In one embodiment, carbon and/or boron are included in an aluminum alloy in an amount up to 2.0 wt. %. In another embodiment, carbon and/or boron are included in an aluminum alloy in an amount up to 1.0 wt. %. Other elements, such as oxygen and nitrogen, may also find use in the alloy (e.g., when in the form of oxides or nitrides). Incidental elements may be present in minor amounts, or may be present in significant amounts, and may add desirable or other characteristics on their own without departing from the alloy described herein, so long as the alloy retains the desirable characteristics described herein. It is to be understood, however, that the scope of this disclosure should not/cannot be avoided through the mere addition of an element or elements in quantities that would not otherwise impact on the combinations of properties desired and attained herein. Some of the above ranges of incidental elements that may be included are given in weight percent. Those skilled in the art can readily convert the weight percentages to atomic percentages as necessary.

[0013] As used herein,“grain refiner” means a nucleant or nucleants that facilitates alloy crystal formation. As it relates to the present alloying systems, a grain refiner may facilitate, for instance, formation of eutectic structures and/or primary phase solidification. In one embodiment, a grain refiner comprises an intermetallic material.

[0014] While this section has generally been described relative to the use of iron as the transition metal used in the new aluminum alloys, other transition metals may be used in lieu of or as a partial substitute for iron. For instance, one or more of chromium (Cr), manganese (Mn), cobalt (Co) and nickel (Ni) may be used in lieu or of or as a partial substitute for iron, and in any of the amounts identified above for the iron content of the new aluminum alloys.

[0015] In one embodiment, chromium fully replaces iron, and thus a new aluminum alloy may include from 1.2 to 4.1 at. % Cr, with iron being present as an impurity. In another embodiment, chromium is partially substituted for iron, and thus a new aluminum alloy may include from 1.2 to 4.1 at. % at. % (Cr+Fe).

[0016] In one embodiment, manganese fully replaces iron, and thus a new aluminum alloy may include from 1.2 to 4.1 at. % Mn, with iron being present as an impurity. In another embodiment, manganese is partially substituted for iron, and thus a new aluminum alloy may include from 1.2 to 4.1 at. % (Mn+Fe).

[0017] In one embodiment, cobalt fully replaces iron, and thus a new aluminum alloy may include from 1.2 to 4.1 at. % Co, with iron being present as an impurity. In another embodiment, cobalt is partially substituted for iron, and thus a new aluminum alloy may include from 1.2 to 4.1 at. % (Co+Fe).

[0018] In one embodiment, nickel fully replaces iron, and thus a new aluminum alloy may include from 1.2 to 4.1 at. % Ni, with iron being present as an impurity. In another embodiment, nickel is partially substituted for iron, and thus a new aluminum alloy may include from 1.2 to 4.1 at. % (Ni+Fe).

[0019] While only combinations of two transition metals are shown above, three or more transition metals may be used in the new aluminum alloys, and the ranges and amounts described above apply to aluminum alloys having three or more transition metals.

[0020] When other transition metals are used in lieu of or in addition to iron, similar intermetallic compounds to a-AlFeSi and Ak,Fe may be formed in the aluminum alloys. Thus, the terms “a-AlFeSi phase” and “Ale(Fe, Mn) phase” also includes chromium- containing, manganese-containing, cobalt-containing and nickel-containing intermetallic compounds, and irrespective of whether iron is contained in those compounds or not. Similarly, the recitation of any ranges or compositions relating to iron also specifically apply to aluminum alloys having chromium, manganese, cobalt and/or nickel, and irrespective of whether iron is included in such aluminum alloys. Thus, all of the ranges and amounts recited in the above paragraphs relating to iron, also apply equally to aluminum alloys having other transition metals of chromium, manganese, cobalt and/or nickel, and irrespective of whether iron is included in such aluminum alloys.

ii. Microstructure

[0021] In one embodiment, a new aluminum alloy comprises from 12 mol. % to 24 mol. % of a-AlFeSi phase. In another embodiment, a new aluminum alloy comprises not greater than 22 mol. % of a-AlFeSi phase. In yet another embodiment, a new aluminum alloy comprises not greater than 20 mol. % of a-AlFeSi phase. In another embodiment, a new aluminum alloy comprises not greater than 18 mol. % of a-AlFeSi phase.

[0022] As used herein, the“a -AlFeSi phase” means the Alo _. 66Feo.i9Sio _. o5(Al,Si)o _.i phase in a Scheil solidification model. As noted below, the PANDAT® computer software employing the“PanA12018b_all” database is used to produce the Scheil solidification models described herein.

[0023] In one embodiment, a new aluminum alloy comprises not greater than 5 mol. % of Ale(Fe, Mn) phases. In another embodiment, a new aluminum alloy comprises not greater than 4 mol. % of Ak,(Fe, Mn) phases. In yet another embodiment, a new aluminum alloy comprises not greater than 3 mol. % of Ak,(Fe, Mn) phases. In another embodiment, a new aluminum alloy comprises not greater than 2 mol. % phases. In yet another embodiment, a new aluminum alloy comprises not greater than 1 mol. % of Ak,(Fe, Mn) phases. In one embodiment, a new aluminum alloy comprises 0% Ah,(Fe, Mn) phases.

[0024] As used herein, the“A (Fe, Mn) phase” means the“A (Fe, Mn) phase” phase in a Scheil solidification model. As noted above, the PANDAT® computer software employing the“PanA12018b_all” database is used to produce the Scheil solidification models described herein.

[0025] The“mol. % of a-AlFeSi phase” and“mol. % of Ale(Fe, Mn) phase” are determined by inputting a specific aluminum alloy composition into the PANDAT® computer software (version 2018.1, dated May 24, 2018) employing the“PanA12018b_all” database (dated May 24, 2018), where the computer software parameters are the following:

• The Scheil solidification model is employed (complete diffusion in the liquid; no diffusion in the solid);

• All phases are suspended in the model except the following:

o Liquid o f_tot(@Alpha_AlFeSi) (i.e., the a-AlFeSi phase);

o f_tot(@Fcc) (i.e., the fee aluminum phase);

o f_tot(@Diamond) (i.e., the Si (diamond) phase); and o f_tot(@A16_FeMn) (i.e., the Ah,(Fe, Mn) phase).

• The aluminum alloy composition shall be input into the PANDAT® computer software, with the following exceptions:

o If any of the following elements are present/used: the Class X elements (i.e., V, Mo, Nb, Ta, and W) and the transition metal substitutes for iron (i.e., Cr, Mn, Co and Ni), the amounts of these elements are added to the total amount of iron. The amounts of these elements shall be added to the amount of iron, even if the total amount of iron exceeds the amount of iron indicated in a disclosed or claimed embodiment in the present application.”

[0026] As a non-limiting example, in accordance with above computer software parameters, an aluminum alloy having 3.0 at. % Fe, 0.5 at. % V, 1.5 at. % Si, and a balance of aluminum is input into the PANDAT® computer software as an aluminum alloy having 3.5 at. % Fe, 1.5 at. % Si, and a balance of aluminum. The output from the PANDAT® computer software for this hypothetical alloy is given in Table 2:

Table 2: PANDAT® Computer Software Output for Hypothetical

Alloy***

f_tot(@Alpha_AlFeSi) is the mole fraction of a-AlFeSi phase;

f_tot(@Fcc) is the mole fraction of fee aluminum phase;

f_tot(@Diamond) is the mole fraction of Si (diamond) phase; and

f_tot(@A16_FeMn) is the mole fraction of Ah,(Fe, Mn) phase.

**NOTE: PANDAT uses the term“f_tot (@A16_FeMn)” irrespective of whether manganese is present.

*** NOTE: based on the limitations of commercially available software (e.g. inability include each and every element in the version of this commercial available software package), but without being bound by any particular mechanism or theory, it is believed the disclosed methodologies of employing the commercially available software and protocols described herein provides an accurate model/prediction of the amount of applicable phases in the Al-(Fe+X)-Si alloys described herein.

[0027] In some embodiments, the new aluminum alloys comprise a fine eutectic-type structure. As used herein, a“fine eutectic-type structure” means an alloy microstructure having regularly dispersed iron-bearing phases, such as regularly dispersed Ak,(Fe, Mn) and/or a-AlFeSi phases, which phases may at least partially make-up one or more of the following types of structures: spheroidal, cellular, lamellar, and wavy eutectic, for instance. In one embodiment, a fine eutectic-type structure comprises at least two of the following strucutres: spheroidal, cellular, lamellar, wavy eutectic, or other. In one embodiment, an aluminum alloy product includes, as a non-limiting example, from 12 to 24 mol.% of a- AlFeSi phases and up to 0.05 mol. % of Ale(Fe, Mn) phases.

[0028] In one embodiment, a new aluminum alloy product comprises a fine eutectic-type structure having an average spacing between eutectic structures (“average eutectic spacing”) of not greater than 10 micrometers. In another embodiment, the average eutectic spacing is not greater than 8 micrometers. In yet another embodiment, the average eutectic spacing is not greater than 6 micrometers. In another embodiment, the average eutectic spacing is not greater than 5 micrometers. In another embodiment, the average eutectic spacing is not greater than 4 micrometers. In yet another embodiment, the average eutectic spacing is not greater than 3 micrometers. In another embodiment, the average eutectic spacing is not greater than 2 micrometers. In yet another embodiment, the average eutectic spacing is not greater than 1 micrometers. In another embodiment, the average eutectic spacing is not greater than 0.5 micrometers.

[0029] As used herein,“average eutectic spacing” means the average spacing between the eutectic structures of the product as determined by the“Heyn Lineal Intercept Procedure” method described in ASTM standard El 12-13, entitled, “Standard Test Methods for Determining Average Grain Size”, wherein the distance between eutectic structures is/are measured as opposed to the grains.

[0030] In some embodiments, an additively manufactured aluminum alloy comprises equiaxed grains. Additively manufactured products that comprise equiaxed grains may realize, for instance, improved ductility and/or strength, among others. In this regard, equiaxed grains may facilitate the realization of improved ductility and/or strength, among others. In one embodiment, an additively manufactured aluminum alloy product comprises equiaxed grains, wherein the average grain size is of from 0.05 to 50 microns.

[0031] As used herein,“equiaxed grains” means grains having an average aspect ratio of less than 4: 1 as measured in the XY, YZ, and XZ planes. The“aspect ratio” is determined using commercial software Edax OIM version 8.0 or equivalent. The commercial software fits an ellipse to the perimeter points of the grain. As used herein,“aspect ratio” is the inverse of: the length of the minor axis of the ellipse divided by the length of the major axis of the ellipse as determined using commercial software. In one embodiment, an additively manufactured aluminum alloy product comprises equiaxed grains having an average aspect ratio of less than 4: 1. In one embodiment, an additively manufactured aluminum alloy product comprises equiaxed grains having an average aspect ratio of not greater than 3: 1. In one described embodiment, an additively manufactured aluminum alloy product comprises equiaxed grains having an average aspect ratio of not greater than 2: 1. In one embodiment, an additively manufactured aluminum alloy product comprises equiaxed grains having an average aspect ratio of not greater than 1.5: 1. In one embodiment, an additively manufactured aluminum alloy product comprises equiaxed grains having an average aspect ratio of not greater than 1.1 : 1. The amount (volume percent) of equiaxed grains in the additively manufactured product in the as-built condition may be determined by EBSD (electron backscatter diffraction) analysis of a suitable number of SEM micrographs of the additively manufactured- product in the as-built condition. Generally, at least 5 micrographs should be analyzed.

[0032] The average size of equiaxed grains of the additively manufactured aluminum alloy product may be not greater than 50 microns. In one embodiment, the average size of the equiaxed grains of the additively manufactured aluminum alloy product is not greater than 40 microns. In another embodiment, the average size of the equiaxed grains of the additively manufactured aluminum alloy product is not greater than 30 microns. In yet another embodiment, the average size of the equiaxed grains of the additively manufactured aluminum alloy product is not greater than 20 microns. In another embodiment, the average size of the equiaxed grains of the additively manufactured aluminum alloy product is not greater than 10 microns. In yet another embodiment, the average size of the equiaxed grains of the additively manufactured aluminum alloy product is not greater than 5 microns. In another embodiment, the average size of the equiaxed grains of the additively manufactured aluminum alloy product is not greater than 4 microns. In yet another embodiment, the average size of the equiaxed grains of the additively manufactured aluminum alloy product is not greater than 3 microns. In another embodiment, the average size of the equiaxed grains of the additively manufactured aluminum alloy product is not greater than 2 microns, or less. In any of these embodiments, the equiaxed grains may be realized in the as-built condition.

[0033] In one embodiment, an additively manufactured aluminum alloy product comprises grains and at least 50 vol. % of the grains are equiaxed grains. In another embodiment, an additively manufactured aluminum alloy product comprises at least 60 vol. % of equiaxed grains. In yet another embodiment, an additively manufactured aluminum alloy product comprises at least 70 vol. % of equiaxed grains. In another embodiment, an additively manufactured aluminum alloy product comprises at least 80 vol. % of equiaxed grains. In yet another embodiment, an additively manufactured aluminum alloy product comprises at least 90 vol. % of equiaxed grains. In another embodiment, an additively manufactured aluminum alloy product comprises at least 95 vol. % of equiaxed grains. In yet another embodiment, an additively manufactured aluminum alloy product comprises at least 99 vol. % of equiaxed grains, or more. In any of these embodiments, the equiaxed grains may be realized in the as-built condition.

[0034] As used herein, the“as-built condition” means the condition of the additively manufactured aluminum alloy product after production and absent of any subsequent mechanical, thermal or thermomechanical treatments.

[0035] As used herein,“grain” takes on the meaning defined in ASTM El 12 §3.2.2, i.e., “the area within the confines of the original (primary) boundary observed on the two- dimensional plane of-polish or that volume enclosed by the original (primary) boundary in the three-dimensional object”.

[0036] As used herein, the“grain size” is calculated by the following equation:

• wherein A i is the area of the individual grain as measured using commercial software Edax OIM version 8.0 or equivalent; and

• wherein vi is the calculated individual grain size assuming the grain is a circle. Grain size is determined based on a two-dimensional plane that includes the build direction of the additively manufactured product.

[0037] As used herein, the“area weighted average grain size” is calculated by the following equation: v-bar - C^ /UvO/ffi^ Ai)

• wherein Ai is the area of each individual grain as measured using commercial software Edax OIM version 8.0 or equivalent;

• wherein vi is the calculated individual grain size assuming the grain is a circle; and

• wherein v-bar is the area weighted average grain size.

[0038] In some embodiments, the aluminum alloy products comprise columnar grains (defined below).

[0039] As used herein,“columnar grains” means grains having an average aspect ratio of at least 4: 1 as measured in the YZ and/or XZ planes, wherein the Z plane is the build direction. The“aspect ratio” is determined using commercial software Edax OIM version 8.0 or equivalent. The commercial software fits an ellipse to the perimeter points of the grain. In one embodiment, columnar grains have an average aspect ratio of at least 5: 1. In another embodiment, columnar grains have an average aspect ratio of at least 6: 1. In yet another embodiment, columnar grains have an average aspect ratio of at least 7: 1. In another embodiment, columnar grains have an average aspect ratio of at least 8: 1. In yet another embodiment, columnar grains have an average aspect ratio of at least 9: 1. In another embodiment, columnar grains have an average aspect ratio of at least 10: 1.

III. Product Forms and Processing

[0040] The new aluminum alloys may be made via any suitable processing route. In one embodiment, the new aluminum alloys are in a cast form such as in the form of an ingot or billet (e.g., for using in making atomized powders). In one embodiment, the new aluminum alloys are in the form of a wrought product, such as in the form of a sheet product, a plate product, a foil product, a forged product, or an extruded product. In one embodiment, the new aluminum alloys are in the form of a powder metallurgy product. In one embodiment, the new aluminum alloys are shape cast. In one embodiment, the processing route involves rapid solidification (e.g., to facilitate production of fine eutectic-type microstructures), such as high-pressure die casting and some continuous castings techniques. In one embodiment, the new aluminum alloys are additively manufactured, as described below. In one embodiment, the new aluminum alloys are in the form of powders or wires (e.g., for use in an additive manufacturing process). In one embodiment, the new aluminum alloys are in the form of sheets (e.g., foils) for use in additive manufacturing processes such as sheet lamination, per ASTM F2792-12a.

[0041] As noted above, the new aluminum alloys described herein may be used to produce aluminum alloy products via powder metallurgy methods. For instance, a powder comprising any of the aluminum alloy compositions described above may be used to produce a powder metallurgy product. In this regard, the powder may be produced by suitable methods, such as by mechanical, chemical, and physical methods (e.g., atomization). For instance, mechanical methods for producing powders may include machining, milling, and/or mechanical alloying. Chemical methods for producing powders may include electrolytic deposition, thermal decomposition, precipitation from a liquid, precipitation from a gas, and/or solid-solid reactive synthesis. In this regard, the powder may comprise alloyed particles (i.e., a chemical mixture of elements) and/or non-alloyed particles (i.e., particles essentially consisting of one element). For instance, any combination of alloyed and non- alloyed powders may be blended to realize an aluminum alloy powder having a composition described herein.

[0042] Aluminum alloy powders may be compacted into final or near-final product form using powder metallurgy methods. For instance, the powder may be compacted via low pressure methods such as, loose powder sintering, slip casting, slurry casting, tape casting, or vibratory compaction. In another aspect, pressure may be used to realize the compaction by methods such as, for instance, die compaction, cold/hot isostatic pressing, and/or sintering. Such methods may facilitate production of crack-free final or near-final aluminum alloy products. In any event, the crack-free powder metallurgy product may be further processed to obtain a wrought final product. This further processing may include any combination of thermal treating (e.g., solution heat treating, annealing) and working steps, described above, as appropriate to achieve the final aluminum alloy product form. Once the final aluminum alloy product form is realized, the material may be precipitation hardened (e.g., naturally aged, artificially aged) to develop strengthening precipitates. The final product form may be a rolled product, an extruded product or a forged product, for instance.

[0043] After their production, the new aluminum alloys may be thermally treated. Thermally treating may include one or more of solution heat treating and quenching, precipitation hardening (aging), and annealing.

[0044] The terms“solution heat treating” and the like (e.g., "solutionizing"), means heating an alloy body to a suitable temperature, generally above a solvus temperature, and holding at that temperature long enough to allow at least some soluble constituents to enter solid solution. Quenching may optionally be employed after a solution heat treatment. The quenching may comprise cooling rapidly enough to hold at least some dissolved element(s) in solid solution. The quenching may facilitate production of a supersaturated solid solution. A subsequent precipitation hardening step may facilitate the production of precipitate phases from a supersaturated solid solution, as discussed in greater detail below.

[0045] In one embodiment, thermally treating an aluminum alloy comprises precipitation hardening. A precipitation hardening step may be employed after production of an aluminum alloy product and/or after solution heat treating and quenching of an aluminum alloy product. For instance, an additively manufactured aluminum alloy product may realize a supersaturated solid solution in the as-built condition (e.g., due to high cooling rates of at least 1000°C/s). Precipitation hardening of the new aluminum alloys may occur at room temperature (sometimes referred to as a“natural age”) and/or at one or more elevated temperatures (sometimes referred to as an“artificial age”). The precipitation hardening may be performed for a time sufficient and at a temperature sufficient to facilitate the production of one or more precipitates. In one embodiment, a precipitation hardening step comprises producing precipitates comprising one or more Class Z elements.

Additive Manufacturing

[0046] The aluminum alloys described herein may be used in additive manufacturing to produce an additively manufactured aluminum alloy body. As used herein, “additive manufacturing” means,“a process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies”, as defined in ASTM F2792-12a entitled “Standard Terminology for Additively Manufacturing Technologies”. Additively manufactured aluminum alloy bodies may be manufactured via any appropriate additive manufacturing technique described in this ASTM standard, such as binder jetting, directed energy deposition, material extrusion, material jetting, powder bed fusion, or sheet lamination, among others. Any suitable feedstocks may be used, including one or more powders, one or more wires, one or more sheets, and combinations thereof. In some embodiments the additive manufacturing feedstock is comprised of one or more powders. In some embodiments, the additive manufacturing feedstock is comprised of one or more wires. In some embodiments, the additive manufacturing feedstock is comprised of one or more sheets. Foil is a type of sheet. [0047] In one embodiment, an additive manufacturing process includes depositing successive layers of one or more powders and then selectively melting and/or sintering the powders to create, layer-by-layer, an additively manufactured aluminum alloy body (product). In one embodiment, an additive manufacturing processes uses one or more of Selective Laser Sintering (SLS), Selective Laser Melting (SLM), and Electron Beam Melting (EBM), among others. In one embodiment, an additive manufacturing process uses an EOSINT M 280 Direct Metal Laser Sintering (DMLS) additive manufacturing system, or comparable system, available from EOS GmbH (Robert-Stirling-Ring 1, 82152 Krailling/Munich, Germany). In one embodiment, additive manufacturing process uses a LENS additive manufacturing system, or comparable system, available from OPTOMEC, 3911 Singer N.E., Albuquerque, NM 87109.

[0048] As one example, a feedstock, such as a powder or wire, comprising (or consisting essentially of) any of the aluminum alloy compositions described above may be used in an additive manufacturing apparatus to produce an additively manufactured aluminum alloy body. In some embodiments, the additively manufactured aluminum alloy body is a crack- free preform. The feedstock may be selectively heated above the liquidus temperature of the material, thereby forming a molten pool having any of the aluminum alloy compositions described above, followed by rapid solidification of the molten pool thereby forming an additively manufactured aluminum alloy product. The additively manufactured aluminum alloy product may realize a fine eutectic-type microstructure.

[0049] As noted above, additive manufacturing may be used to create, layer-by-layer, the aluminum alloy product. In one embodiment, a metal powder bed is used to create a tailored aluminum alloy product. As used herein a“metal powder bed” means a bed comprising a metal powder. During additive manufacturing, particles of the same or different compositions may melt (e.g., rapidly melt) and then solidify (e.g., in the absence of homogenous mixing). Thus, products having a homogenous or non-homogeneous microstructure may be produced. One embodiment of a method of making an additively manufactured aluminum alloy body may include (a) dispersing a powder comprising any of the aluminum alloy compositions described above, (b) selectively heating a portion of the powder (e.g., via a laser) to a temperature above the liquidus temperature of the particular body to be formed, (c) forming a molten pool having any of the aluminum alloy compositions described above, and (d) cooling the molten pool at a cooling rate of at least 1000°C per second. In one embodiment, the cooling rate is at least 10,000°C per second. In another embodiment, the cooling rate is at least 100,000°C per second. In another embodiment, the cooling rate is at least 1,000,000°C per second. Steps (a)-(d) may be repeated as necessary until the aluminum alloy body is completed, i.e., until the final additively manufactured aluminum alloy body is formed / completed. The final additively manufactured aluminum alloy body may be of a complex geometry, or may be of a simple geometry (e.g., in the form of a sheet or plate), and may realize a fine eutectic-type microstructure. After or during production, an additively manufactured aluminum alloy product may be deformed (e.g., by one or more of rolling, extruding, forging, stretching, compressing).

[0050] The powders used to additively manufacture an aluminum alloy body may be produced by atomizing a material (e.g., an ingot or melt) of the new alloy aluminum alloys into powders of the appropriate dimensions relative to the additive manufacturing process to be used. As used herein,“powder” means a material comprising a plurality of particles. Powders may be used in a powder bed to produce a tailored alloy product via additive manufacturing. In one embodiment, the same general powder is used throughout the additive manufacturing process to produce an aluminum alloy product. For instance, the final tailored aluminum alloy product may comprise a single region / matrix produced by using generally the same metal powder during the additive manufacturing process. The final tailored aluminum alloy product may alternatively comprise at least two separately produced distinct regions. In one embodiment, different metal powder bed types may be used to produce the aluminum alloy product. For instance, a first metal powder bed may comprise a first metal powder and a second metal powder bed may comprise a second metal powder, different than the first metal powder. The first metal powder bed may be used to produce a first layer or portion of the alloy product, and the second metal powder bed may be used to produce a second layer or portion of the alloy product. As used herein, a“particle” means a minute fragment of matter having a size suitable for use in the powder of the powder bed (e.g., a size of from 5 microns to 100 microns). Particles may be produced, for example, via atomization.

[0051] The additively manufactured aluminum alloy body may be subject to any appropriate working steps. If employed, the working steps may be conducted on an intermediate form of the additively manufactured body and/or may be conducted on a final form of the additively manufactured body. In one embodiment, an additively manufactured body consists essentially of any of the aluminum alloy compositions described above.

[0052] In another embodiment, an aluminum alloy body is a preform for subsequent working. A preform may be an additively manufactured product. In one embodiment, a preform is of a near net shape product that is close to the final desired shape of the final product, but the preform is designed to allow for subsequent working to achieve the final product shape. Thus, the preform may be worked such as by forging, rolling, extrusion, or hipping (hot isostatic pressing) to produce an intermediate product or a final product, which intermediate or final product may be subject to any further appropriate working or thermal steps (e.g., stress relief), as described above, to achieve the final product. In one embodiment, the working comprises hipping to compress the part. In one embodiment, an aluminum alloy preform may be compressed and porosity may be reduced. In one embodiment, the hipping temperature is maintained below the incipient melting point of the aluminum alloy preform. In one embodiment, the preform may be a near net shape product.

[0053] In one approach, electron beam (EB) or plasma arc techniques are utilized to produce at least a portion of the additively manufactured aluminum alloy body. Electron beam techniques may facilitate production of larger parts than readily produced via laser additive manufacturing techniques. In one embodiment, a method comprises feeding a wire (e.g., < 5 mm in diameter) of the new aluminum alloys described herein to the wire feeder portion of an electron beam gun. The wire may be of the compositions, described above. The electron beam (EB) heats the wire above the liquidus point of the body to be formed, followed by rapid solidification (e.g., at least 100°C per second) of the molten pool to form the deposited material. The wire could be fabricated by a conventional ingot process or by a powder consolidation process. These steps may be repeated as necessary until the final aluminum alloy body is produced. Plasma arc wire feed may similarly be used with the aluminum alloys disclosed herein. In one embodiment, not illustrated, an electron beam (EB) or plasma arc additive manufacturing apparatus may employ multiple different wires with corresponding multiple different radiation sources, each of the wires and sources being fed and activated, as appropriate to provide the aluminum alloy product.

[0054] In another approach, a method may comprise (a) selectively spraying one or more metal powders of the new aluminum alloys described herein towards a building substrate, (b) heating, via a radiation source, the metal powders, and optionally the building substrate, above the liquidus temperature of the product to be formed, thereby forming a molten pool, (c) cooling the molten pool, thereby forming a solid portion of the product, wherein the cooling comprises cooling at a cooling rate of at least 100°C per second. In one embodiment, the cooling rate is at least 1000°C per second. In another embodiment, the cooling rate is at least 10,000°C per second. The cooling step (c) may be accomplished by moving the radiation source away from the molten pool and/or by moving the building substrate having the molten pool away from the radiation source. Steps (a)-(c) may be repeated as necessary until the product is completed. The spraying step (a) may be accomplished via one or more nozzles, and the composition of the metal powders can be varied, as appropriate, to provide a tailored final aluminum alloy product. The composition of the metal powder being heated at any one time can be varied in real-time by using different powders in different nozzles and/or by varying the powder composition(s) provided to any one nozzle in real-time. The work piece can be any suitable substrate. In one embodiment, the building substrate is, itself, a metal product (e.g., an alloy product, such as any of the aluminum alloy products described herein.)

IV. Product Applications

[0055] The new aluminum alloys described above may be suitable for elevated temperature applications. For instance, the new aluminum alloy bodies of the new aluminum alloys described herein may be suitable in aerospace and/or automotive applications. In one embodiment, a new aluminum alloy is used in a ground transportation application. Non limiting examples of aerospace applications may include heat exchangers and turbines (e.g., turbocharger impeller wheels). Non-limiting examples of automotive applications may include interior or exterior trim/appliques, pistons, valves, and/or turbochargers. Other examples include any components close to a hot area of the vehicle, such as engine components and/or exhaust components, such as the manifold.

[0056] Aside from the applications described above, the new aluminum alloy bodies of the present disclosure may also be utilized in a variety of consumer products, such as any consumer electronic products, including laptops, cell phones, cameras, mobile music players, handheld devices, computers, televisions, microwave, cookware, washer/dryer, refrigerator, sporting goods, or any other consumer electronic product requiring durability and selective visual appearance. In one embodiment, the visual appearance of the consumer electronic product meets consumer acceptance standards.

[0057] In some embodiments, the new aluminum alloy bodies of the present disclosure may be utilized in a variety of products including non-consumer products including the likes of medical devices, transportation systems and security systems, to name a few. In other embodiments, the new aluminum alloy bodies may be incorporated in goods including the likes of car panels, media players, bottles and cans, office supplies, packages and containers, among others. [0058] As noted above, the new aluminum alloys may be used in a variety of product applications. In this regard, at least a portion of a product (e.g., an additively manufactured product) may comprise any of the new aluminum alloy compositions described above. For instance, at least a portion of an aluminum alloy product may comprise one of the new aluminum alloy compositions, and at least one other portion may be comprised of a different material (e.g., a different aluminum alloy). Furthermore, the new aluminum alloy compositions may be present in a product comprising a compositional gradient (i.e., a graded product). At least a portion of a graded product may comprise any of the new aluminum alloy compositions described above.

[0059] The figures constitute a product of this specification and include illustrative embodiments of the present disclosure and illustrate various objects and features thereof. In addition, any measurements, specifications and the like shown in the figures are intended to be illustrative, and not restrictive. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0060] Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying figures. Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the invention that may be embodied in various forms. In addition, each of the examples given in connection with the various embodiments of the invention is intended to be illustrative, and not restrictive.

[0061] Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The phrases“in one embodiment” and“in some embodiments” as used herein do not necessarily refer to the same embodiment s), though it may. Furthermore, the phrases“in another embodiment” and “in some other embodiments” as used herein do not necessarily refer to a different embodiment, although it may. Thus, as described below, various embodiments of the invention may be readily combined, without departing from the scope or spirit of the invention.

[0062] In addition, as used herein, the term "or" is an inclusive "or" operator, and is equivalent to the term "and/or," unless the context clearly dictates otherwise. The term "based on" is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meaning of "a," "an," and "the" include plural references, unless the context clearly dictates otherwise. The meaning of "in" includes "in" and "on", unless the context clearly dictates otherwise.

[0063] While a number of embodiments of the present invention have been described, it is understood that these embodiments are illustrative only, and not restrictive, and that many modifications may become apparent to those of ordinary skill in the art. Further still, unless the context clearly requires otherwise, the various steps may be carried out in any desired order, and any applicable steps may be added and/or eliminated.