Difference in adiabatic shear susceptibility between pure copper and Cu–30% Zn solid solution alloy at different strain rate

The difference in adiabatic shear susceptibility between pure copper and Cu–30% Zn alloy with similar grain size was investigated. The results show that the Cu–30% Zn alloy has a similar strain hardening, lower strain rate hardening, and higher thermal softening than pure copper at the strain rate of 5.0 × 104s−1, which together lead to a higher adiabatic shear susceptibility. However, the flow stress of Cu–30% Zn alloy decreases when the strain rate is increased to 6.0 × 104s−1, showing a negative strain rate hardening effect because of dynamic strain aging. The reason why dynamic strain aging occurred is adiabatic temperature rise promotes the rapid diffusion of solute atoms around the dislocation to form atom atmosphere and pin dislocations, and the high strain rate causes the movement rate of dislocations to be higher than that of atom atmosphere under the action of the dislocation stress field.Graphical abstract