GB638733A - Improvements in and relating to zinc casting alloys - Google Patents

Abstract

An alloy particularly suitable for die casting has the following composition: Al 1.0-4.5 per cent, Cu 1.0-3.5 per cent, Be 0.05-0.5 per cent, Zn the remainder. The alloy may also contain 0.02-0.06 per cent Mg and impurities such as Fe up to 0.075 per cent, Pb up to 0.003 per cent, Cd up to 0.003 per cent and Sn up to 0.001 per cent. Cu-Be, Zn-Cu-Be or Al-Be master alloys may be used in the production of the alloys of the invention. Two examples of the following compositions are referred to: (1) Al 4.0 per cent, Cu 2.7 per cent, Be 0.13 per cent, Zn the balance; (2) Al 4.0 per cent, Cu 1.0 per cent, Be 0.20 per cent, Zn the balance. These alloys may be hot worked at 275-350 DEG C and then cold worked to effect a cold reduction of up to 50 per cent. These alloys may be cast in preheated graphite moulds, solution treated at 365 DEG C, quenched and aged for 4 hours at temperatures between 75 DEG C and 350 DEG C. Alternatively, they may be hot swaged at 320 DEG C, heated for 2 hours at 365 DEG C, quenched in water, aged for 4 hours at 75 DEG C, cold swaged to effect a reduction of 50 per cent and aged for 4 hours between 75 DEG C and 300 DEG C.