Effect of Melt Homogeneity on the Age-hardening of Copper-Chromium Alloys

Abstract

Copper-chromium alloys are treated with rare earths to impart higher homogeneity within the melts. The age-hardening behaviour of the alloys are studied and are compared with the alloy without rare-earth treatment. Also, copper chromium alloys are subjected to vibration during solidification to induce a greater structural fineness. The ageing behaviours of the vibrated alloys are compared with those of the rare-earth treated alloys. It is observed that rare-earth treatment leads to finer dispersion of chromium precipitates. It is noted that higher strength properties at a relatively high level of conductivity are achievable in rare-earth-treated alloys. Also, superimposition of vibration during solidification of copper-chromium is found to have led to higher aged hardness with a fall in conductivity.