Effect of grain size on high strain rate deformation of copper

Abstract

Experiments were performed to observe the deformation characteristics of oxygen-free high-conductivity (OFHC) copper at high strain rates (up to 40,000 s−1) and to relate differenc in grain size with differences in deformation behavior. The rod impact and torsional Hopkinson bar test methods were used in these experiments. Results show that grain size reductions substantially reduce surface irregularities that develop during deformation. The effect of grain size on the yield stress and on the strain-hardening behavior of copper is small and is similar to the effect of grain size in copper at quasistatic strain rates. The observation that grain size has a substantial effect on surface irregularities may have important implications for applications in which stable deformation of thin sections is of concern.