Critical grain size for dislocation storage and consequences for strain hardening of nanocrystalline materials

Abstract : We consider strain hardening of nanostructured materials and propose a physically based interpretation of their low strain hardening capability in terms of a reduced storage rate of dislocations. The model suggested provides a modification of the Kocks–Mecking–Estrin evolution law for dislocation storage for nanostructured materials and predicts a critical grain size below which the strain hardening rate drops off.