Effect of stacking fault energy and strain rate on the mechanical properties of Cu and Cu alloys

The effect of stacking fault energy (SFE) and strain rate on the mechanical properties of Cu, Cu-10 wt%Zn and Cu-20 wt%Zn alloys prepared by rolling and Split Hopkinson Pressure Bar (SHPB) impact has been investigated. Using tensile tests, we demonstrated that the Cu and Cu alloys exhibited a combination of significantly enhanced strength and ductility with decreasing SFE when the samples were deformed at the same quasi-static strain rate of rolling. Meanwhile, the Cu and Cu alloys exhibited slightly higher strength and remarkably better ductility when the materials were deformed by rolling at a quasi-static strain rate (10−4-10−2 s−1), compared to the materials deformed by SHPB at a dynamic strain rate (104 s−1) with the same SFE. The Cu and Cu alloys processed at the high strain rate resulted in the occurrence of shear bands and fractures, which led to a decrease in both the strength and ductility of the materials.