GB633154A - An improved aluminium base alloy - Google Patents

Abstract

An aluminium base alloy, particularly suitable for the manufacture of pistons, air-cooled cylinder heads and other parts operating at high temperatures, has the following composition: Cu 1.91-5.00 per cent, Ni 0.50-3.50 per cent, Mn 0.31-0.99 per cent, Mg 0.60-2.25 per cent, Si 0.02-2.60 per cent, Fe 0.02-2.00 per cent, Al the remainder, but so that the total of the Cu, Ni, Mn and Si contents exceeds 3.0 per cent and so that when the Mg content is 0.85 per cent and below the Ni content will be below 1.80 per cent. The alloy may contain one or more of the grain refining elements Ti, Nb, Ce and B up to a total of 1.00 per cent and individually not exceeding 0.75 per cent. The alloy may contain one or more of the elements Sb, Sn, Tl, Te, Pb, Yt, Zn, Cd, Zr, Bi, V, Ta, Th, Li, La, Co, Ag, Cu, Be, Mo, W, As and Ga not exceeding a total of 1.5 per cent and individually not exceeding 1.0 per cent, the Zn content always being below 0.10 per cent and the Pb content being less than 0.20 per cent when the Cu content is 4.0 per cent and over. One or more of Na, K, Ba and P may be present up to a total of 0.25 per cent. C may be present as an impurity. Cr may be present up to 0.49 per cent. The alloy may be artificially aged at 300 DEG C. for a time of up to about 50 hours or it may be solution treated at 470 DEG -570 DEG C. for a time exceeding 1 minute and preferably exceeding 30 minutes followed by quenching in water or other medium. The solution treatment may be followed by artificial ageing between 50 DEG and 300 DEG C. for at least 1 minute up to about 50 hours.