| 摘要 |
A method is provided for producing a metal article from an Al-Si-Mn powder alloy. The alloy is produced by alloying elements in a molten state and a powder of the alloy is produced by atomization. Powder is heated, worked into a finished article of at least 99% density. A metal article produced has a coefficient of thermal expansion less than 11.0 x 10-6 inch/inch/.degree.F and relatively high strength at temperatures greater than 400.degree.F (478.degree.K). Article produced is ideally suited for uses, such as pistons, requiring limited thermal expansion while maintaining high temperature strength. An aluminum base powder alloy provided consists essentially of 10 to 25% Si, 2 to 5% Mn, the balance essentially aluminum and incidental elements and impurities, and is substantially free of Mg, Zn and Ni. Additive elements may be Fe or Cu and Cr, V, Zr and Ti. The powder alloy can be atomized in a temperature range of 1400 to 1600.degree.F (1033 to 1144.degree.K). |
