Abstract
Studies on the properties of Cu-S-Ti and Cu-S-Zr alloys containing 0.8-1.6 at% S, and 0.4-2.7 at% Ti or Zr were carried out. Titanium and zirconium formed (Ti, Cu)S and (Cu, Zr)2S, respectively, which were uniformly dispersed. Age-hardening phenomena were observed in the alloys having the composition ratio of Ti/S>1 or Zr/S>1, which indicates that the soluble titanium and zirconium in the Cu-matrix after formation of sulfide result in age-hardening. (Ti, Cu)S and (Cu, Zr)2S were found to be the effective inclusions for improving the machinability. The Cu-S-Ti and Cu-S-Zr alloys developed by sulfide dispersion are very promising as a new type of copper-based alloys having high strength, high electrical conductivity and good machinability.
