GB621617A - Aluminium alloy - Google Patents

Abstract

An article of aluminium base alloy is formed from an alloy having the following composition:-Mg 1 to 3.5 per cent, Ag 0.20 to 2.0 per cent, Mn 0.5 to less than 1 per cent, Al the remainder, and solutio-treated at 450 DEG to 550 DEG C. for 1 to 20 hours, quenched and aged at 120 DEG to 200 DEG C. for 8 to 30 hours. It is preferably solution-treated at a temperature not less than 520 DEG C. and aged at a temperature not less than 160 DEG C. The above alloy may contain Si up to 0.35 per cent, Ni up to 2.00 per cent, one or more of the elements Fe, Zn, Co and Zr up to not more than 1 per cent of any one, one or more of the elements Sb, Sn and Cr but so that not more than 0.5 per cent of any one of them is present; one or more of the elements Cu, Ti, Be, V, W, Nb, Ce and the rare earth metals, e.g. Misch Metal, but so that not more than 0.30 per cent of any one element is present and not more than 1.0 per cent in total, Misch Metal being permissible up to 1 per cent, one or more of the elements Li, Cd, Ca, Sr, Ba, Th, As, Pb, Bi, but so that not more than 0.1 per cent of any one element is present and not more than 0.3 per cent in total. The alloy does not contain Ni from 0.6 to 1.3 per cent, Co from 0.1 to 0.3 per cent, and Cr from 0.15 to 0.4 per cent when these elements are taken together. The alloy may be cast or forged. With forgings cold working may be carried out either after solution-treatment and before ageing or after the full heat treatment. Specification 468,001 is referred to.