This application is a continuation-in-part of application Serial No. 983,970, filed December 1, 1992.

Technical Field This invention relates to a cast alloy article and a method of making a cast alloy article suitable for improving the combustion characteristics and efficiency of a liquid fuel brought into contact with the article.

Background Art Brown U.S. Patent No. 4,429,665 suggests using a metal bar comprising an alloy of nickel, zinc, copper, tin and silver to improve the combustion characteristics of a liquid fuel that is passed over the surface of the metal bar. Craft U.S. Patent Nos. 3,448,034 and 3,486,999 as well as Gomez U.S. Patent No. 4,959,155 disclose cast alloys having fluids passed thereover for different purposes.

Disclosure of the Invention A cast alloy article made in accordance with a particular method has a shiny, coarse, and irregular surface contour of interspersed peaks, valleys and pores that provide for increased surface area for increased fluid contact and for increased turbulence in fluid flow. The article has interspersed dendritic and interdendritic areas having selected proportions of several metals. The method of making includes heating selected quantities of selected metals including copper, zinc, nickel and tin to a high temperature above about 2000°F. but not in excess of 2400°F., thoroughly intermixing the heated metals, pouring the mixed heated metals into a sand mold having sand having a selected mesh size, slowly cooling the

heated metals immediately after reaching the high temperature, and retaining the poured body at a temperature between about 2000°F. and 800°F. for a period of about 24 hours for slow cooling to form interspersed dendritic areas and interdendritic areas. A cast alloy article of a particular shape enhances surface area contact and turbulence in fluid flow. A liquid fuel passed over the core has been found to improve the combustion efficiency and characteristics of the liquid fuel.

Brief Description of the Drawings

Details of this invention are described in connection with the accompanying drawings which like parts bear similar reference numerals in which: Figure 1 is a side elevation view of a cast alloy article embodying features of the present invention with portions of the housing and inlet and outlet pipes broken away to show internal parts.

Figure 2 is a sectional view taken along line 2-2 of Figure 1.

Figure 3 is an optical microscope photograph of the cast alloy article shown in Figure 1 at 8 power magnification.

Figure 4 is an optical microscope photograph of the cast alloy article at 20 power magnification.

Figure 5 is a scanning electron microscope of the cast alloy article at 100 power magnification.

Figure 6 is a scanning electron microscope of the cast alloy article at 100 power magnification with the target showing a pore.

Figure 7 is a scanning electron microscope of a segment of the cast alloy article of Figure 4 at 500 power magnification.

Figure 8 is a scanning electron microscope of the cast alloy article at 350x power magnification.

Detailed Description

A cast alloy article shown embodying features of the present invention is formed as a fluted cylindrical body 12 of a selected diameter and selected length. The cast alloy body 12 shown has a generally circular cross section with two intermediate longitudinal grooves 13 and 14 and two side longitudinal grooves 15 and 16 in each half section which form channels along which a fluid in contact with the surface will flow. This shape or configuration has been found to provide increased surface area contact and provide turbulence in the flow of the fluid over the body. The cast body 12 is mounted in a cylindrical housing 17, preferably made of copper, with an inlet pipe 18 and an outlet pipe 19 coupled thereto to pass fluid over the cast body 12.

Referring now to Figures 3-8 the cast body 12 has a shiny, coarse, irregular surface contour of interspersed peaks 21, valleys 22 and pores 23. This surface contour increases the surface contact area for the fluid flowing thereover. This coarse, irregular surface containing pores also produces turbulence in the fluid flow.

A cast alloy article made according to a method of the present invention uses selected quantities of copper, zinc, nickel and tin which are heated to a temperature of above about 2000°F. but not in excess of 2400°F. An example of selected quantities by weight are: copper about 46-50% nickel about 19-23% zinc about 21 to 24% tin about 6 to 10% Optimal or preferred quantities are : copper about 48% nickel about 21% zinc about 23% tin about 8%

The heated metals are thoroughly intermixed and then poured into a sand mold with the sand preferably between about 80 mesh to 140 mesh to provide the coarseness and irregularity in the surface. The optimal or preferred is about 120 grain olivine or about 100 black. During the mixing and melting selected quantities of metal are added to attain the desired metal proportions. The heated metals are slowly cooled after reaching the highest temperature. The mold size is thick enough to allow slow cooling. The mold size is short enough to be sure molten alloy is liquid enough at both ends. Each core or cast body 12 is sized to flow rate to accomplish turbulent flow. The poured body is retained at a temperature of between 2000°F. and 800°F. for a period of about 24 hours to provide for a slow cooling.

A slow cooling achieves the proper crystalline structure. This forms dendritic areas 26 and interdendritic areas 27. The cast alloy article has a cast microstructure with a dendritic appearance. Dendrites are solid crystals that become evident as the cast metals slowly cool through the solidification range. Dendrites grow during solidification until they interfere with each other. Each dendritic area is solid dendrites and has a tree branching pattern. Referring now to Figures 7 and 8 the light colored continuous region or area is the dendritic area. The darker, grey particles are the interdendritic areas. The center to center spacing between each tree-like branch of the dendrites is about 0.001 to 0.002 inch. The solid dendrites have by weight percent about 53% copper, about 23% nickel, about 20% zinc and about 3% tin. Each interdendritic area is solid metal preferably having a weight percent of about 34% copper, about 27% nickel, about 7% zinc and about 30% tin. The above cast alloy article when placed in a core and has liquid fuel passed in contact therewith via

the inlet and outlet pipes has been found to enhance the combustion characteristics and efficiency of a liquid fuel such as gasoline and diesel fuel. In particular, laboratory tests run on stationary engines revealed significant changes in aromatics, olefins and saturates as a result of passing the fuel over a cast alloy article in a housing as shown and described herein. The article has shown increased efficiency, cleaner burning and a reduction in pollutant emissions including hydrocarbons, carbon monoxide and oxides of nitrogen.

Although it is not fully understood, the flow of the fuel over the cast alloy article is believed to alter the fuel so as to cause more efficient combustion. This action has been explained as a catalytic treatment action caused by the surface of the article. It is believed that when the fuel flows over the surface there is a natural movement of electrons induced at the fluid interface surfaces which, in turn, activates the electrons in the fuel and turbulent mixing occurs because of the rough surface. It is theorized that as more electrons are activated and the fuel molecules are turbulently mixed. These molecules re-arrange into smaller clusters which enhance the combustion process as smaller fuel molecules are easier to vaporize and, in turn, burn more completely during the combustion cycle.

Improved results particularly for enhanced combustion efficiency of liquid fuels have been obtained by increasing the content of the zinc.

An example of a range of quantities by weight with increased zinc are:

Copper 41-45%

Nickel 18-24%

Zinc 27-31%

Tin 6-8% Two specific examples of selected quantities by weight for the article having more zinc than the prior

examples are :

The procedure followed for making the cast alloy article for the above articles with increased zinc was as follows. The furnaces were started and 60 pounds of the material to be heated was put in a crucible disposed on a fire. While the crucible and contents were heated the molds containing sand were prepared. The material in the crucible was heated to 2200 ^β F. and the temperature was continuously tested by a probe. Next the mold was heated with a torch to remove the water from the sand. This was necessary to reduce flashing of the metals during pouring caused by the increase in zinc content and temperature.

Throughout the process of bringing the alloy to the required temperature zinc had been lost under the prior process as zinc would escape as smoke and gas. Whenever necessary, a covering of sand was placed on the surface of the molten metal to reduce the amount of zinc that became gaseous and enter the air. This was repeated whenever zinc started to be lost.

Immediately before the pour, the temperature was verified by probe to be at 2200°F. Then six pounds of zinc (or about 10% of the total batch) was plunged to the bottom of the crucible and stirred. The mixture was poured into the molds and allowed to cool for a period of 24 hours. The batch was tested and had succeeded in increasing the amount of zinc retained by about 43%. These cores had a substantially higher electrical conductivity than by the previously described article with less zinc.

Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof.