Grain size effect on strain-rate dependence of mechanical properties of polycrystalline copper

This work illustrates the grain size effect on strain-rate dependence of mechanical properties of polycrystalline copper through experimental characterisations and numerical calculations. The as-received and annealed samples with different grain sizes are prepared. Mechanical properties at high strain rates are experimentally attained by using a split Hopkinson pressure bar device. With the increase of grain size, dynamic flow stress decreases, but strain-rate dependence of flow stress increases. Johnson–Cook constitutive model is applied to carry out a numerical analysis about the grain size effect on strain-rate dependence of mechanical data and the quantificational illustrations are given.