Grain-size effect on the properties of materials under dynamic deformation

Some deformation features in fine-grained copper under gradient dynamic stresses are studied which provide a better understanding of the mechanism of the processes involved. The experimentally observed abrupt change in the properties of materials with grain sizes smaller than a certain critical value is shown to be related to intergranular slip during deformation. Materials with a grain size of 5–50 $\mu$m are found to exhibit properties characteristic of nanomaterials with a strain rate varying from 10$^4$ to 3 $\cdot$ 10$^6$ sec$^{-1}$.