GB533880A - Improvements in and relating to the production of copper base alloys - Google Patents

Abstract

533,880. Alloys; annealing. MALLORY METALLURGICAL PRODUCTS, Ltd. (Mallory & Co., Inc., P. R). Dec. 8, 1939, No. 31814. [Classes 72 and 82 (i)] [Also in Group XXII] Copper alloys capable of being age-hardened contain 0.1-2.4 per cent. of cadmium, 0.22-2.5 per cent. of chromium, and 0.05 - 5 per cent. of silicon, with or without 0.002 - 001 per cent. of lithium, up to 1 per cent. of silver, and small amounts of one or more of the metals magnesium, calcium, zinc, aluminium, titanium, zirconium, tin, manganese, iron, nickel, and cobalt. In making the alloys, chromium and silicon may be added in finely divided form, preferably briquetted, to a copper-cadmium alloy; or a copper-chromium-silicon hardeneralloy may be used ; or a copper alloy relatively high in chromium, cadmium, and silicon may be diluted with copper as required. Lithium is preferably added just before pouring. Heattreatment may comprise heating to 600-1000‹C., quenching, and heating to 350 - 600‹C. for 10 minutes to 20 hours. This may be followed by cold working to obtain a reduction of about 20 per cent. and further cold working up to 50 per cent, or more may be employed, further to increase the hardness. A series of cold reductions may be applied alternately with heating to 400 - 500‹C. The alloys may be hot worked prior to the heat-treatment.