Aluminum casting alloy for high strength/high temperature applications

Abstract

An aluminum casting alloy consisting of, by weight, of 7.0-13.0% copper, 0.4-1.2% manganese, 0.21-40% vanadium, 0.31-0.70% zirconium; impurities limited to: less than to 0.6% Si, less than 0.8% Fe, less than 0.2% zinc, less than 0.1% Mn, less than 0.2% Ni, and the remainder being essentially aluminum. There is an absence of titanium, cobalt, molybdenum, tungsten, chromium, boron, tantalum, and niobium. The alloy has, at room temperature, a UTS of about 61 ksi, a YS of about 49 ksi, a tensile elongation of about 6%, and tensile modulus elasticity of about 11.5 MSI, a compressive yield strength of about 53 ksi, a compressive modulus of elasticity of about 18 MSi; high temperature physical properties at 500.degree. F., after 1000 hours exposure to 500.degree. F., comprise a tensile strength of 33 ksi or greater, a tensile yield strength of 23 ksi or greater, a tensile elongation of about 9%, and tensile modulus of elasticity of 10 msi. The alloy is fabricated by a) squeeze casting an aluminum alloy melt of such character; (b) extracting the solidified casting from the die and heat treating the casting to dissolve all alloying elements (i.e., 995.degree.-1018.degree. F. for 7-20 hours); and (c) aging the solution treated casting to achieve improved strength characteristics (i.e., in the range of 340.degree.-400.degree. F. for 5-20 hours).