GB598328A - Aluminium base alloys - Google Patents

Abstract

An aluminium base alloy has the following composition: Cu 0.21-1.09 per cent, Zn 3.50-6.50 per cent, Ni 1.51-5.50 per cent, Mn 0.39-4.00 per cent, Mg 1.50-5.00 per cent, Fe 0.02-0.80 per cent, Si 0.02-1.00 per cent, Nb 0.0-0.30 per cent, Ta 0.0-0.30 per cent, Al the remainder, in which the total percentage of Ni and Mn exceeds 2.00, the Ni percentage always exceeding 2.00 unless Zn percentage is below 6.00 and Mg percentage does not exceed 2.50 unless either Nb or Ta or both are present in quantity exceeding 0.01 per cent and preferably exceeding 0.05 per cent. The alloy may also contain one or more of Sb, Sn, Ce, Ca not exceeding 1.75 per cent in total and it may contain one or more of Ti, Co, Be, Cr, Mo, Li, Ag, Te, Tl, Th, W, V, B, Zr, La and Yt not exceeding a total of 0.60 per cent, and individually not exceeding 0.50 per cent. One or more of Bi, Pb, Cd, As, Na, Ba and P may be present in the alloy not exceeding 1.00 per cent in total, Pb being absent if Si and Fe are each present in amounts of 0.40 per cent and over. The alloy may be subjected to solution heat treatment at a temperature not exceeding 545 DEG C. for at least 20 minutes followed by natural ageing or ageing at 100-150 DEG C. for at least 1/2 hour. Specification 476,930 is referred to.