GB538683A - Aluminium alloy - Google Patents

Abstract

538,683. Alloys ; annealing. HALL, H. C. Feb. 9, 1940, No. 2519. [Classes 72 and 82 (i)] Aluminium alloys particularly suitable for large castings contain 2.2-3.2 per cent. of silicon, 0.06-0.28 per cent. of cobalt up to half of which may be replaced by twice as much nickel, 0.05- 0.25 per cent. of chromium up to half of which may be replaced by one or more of the metals manganese, molybdenum, tungsten, and vanadium, 0.3-0.85 per cent. of copper up to one third of which may be replaced by silver, and 0.1-0.45 per cent. of magnesium. Small amounts of one or more of the following metals may also be present: iron, titanium, beryllium, lithium, cerium, zirconium, niobium, tin, lead, bismuth, cadmium, zinc, sodium, potassium, and calcium. In making the alloys, one or more rich alloys of aluminium with copper, chromium, cobalt, and silicon may be used ; or two or more of such alloys may be first melted together. The alloys may be heat-treated at 510-540‹C. with or with out subsequent ageing which may be at 175‹C. Specification 435,279 is referred to.