Effect of heat treatment on microstructure and mechanical properties of twin roll cast and sequential warm rolled ZK60 alloy sheets

Microstructure and mechanical properties of ZK60 alloy sheets were investigated under solution treatment and artificial aging conditions. Solution treatment at 375 °C for 3 h and subsequent artificial aging treatment at 175 °C for 10 h can be considered to be the optimum T6 treatment. The uniformity of tensile properties was improved and fine equiaxed structure was obtained at this optimum T6 treatment condition. The distribution of Zn and Zr elements was also observed by transmission electron microscope (TEM). Zn can be found in rod-like β′1β′1 precipitates and disc-shaped β′2β′2 precipitates. Zr was found in disc-shaped β′2β′2 or irregular shaped particles, but Zr was not found in the rod-like β′1β′1 precipitates.