GB618700A - A new aluminium base alloy - Google Patents

Abstract

An aluminium base alloy has the following composition: Cu 1.50-5.50 per cent, Cr 0.50-2.00 per cent, Mg 0.60-3.20 per cent, Fe 0.55-2.00 per cent, Ti 0.01-4.50 per cent, Si 0.01-2.00 per cent, Al the remainder which may contain C as an impurity. The total of the Cu and Mg contents always exceeds twice the Cr content and the Mg content always exceeds 1.0 per cent unless the Si content is below 0.50 per cent. The alloy may contain not more than 1.75 per cent of Mn which is always less than the Cr content. Up to 1.50 per cent of Co may be included when Mn is absent or does not exceed 0.25 per cent. The alloy may contain one or more of Sb, Sn, Ca, Be, Ni, Bi, Cd, Nb, La, Pb, Mo, Ga, Ag, Ta, Te, Tl, Th, B, W, V, Yt, Zn, Zr up to 0.60 per cent of each and up to 1.20 per cent in total but so that the Ni content is always less 0.50 per cent unless the Mn content is less than 1.0 per cent, and the Pb content is below 0.20 per cent and will be absent unless the Cr content is above 1.0 or the Si content below 0.40 per cent. One or more of Na, K, Ba, Sr and P may be present up to a total of 0.30 per cent. The alloy may be used as a sand casting or a die casting or worked part which is given an ageing treatment up to 250 DEG C. for a period not exceeding 30 hours. The ageing treatment may be preceded or replaced by a solution treatment at a temperature not exceeding 540 DEG C. for a period not exceeding 36 hours.