Analysis of the Temperature and Strain-Rate Dependences of Strain Hardening

A classical constitutive modeling-based Ansatz for the impact of thermal activation on the stress–strain response of metallic materials is compared with the state parameter-based Kocks–Mecking model. The predicted functional dependencies suggest that, in the first approach, only the dislocation storage mechanism is a thermally activated process, whereas, in the second approach, only the mechanism of dynamic recovery is. In contradiction to each of these individual approaches, our analysis and comparison with experimental evidence shows that thermal activation contributes both to dislocation generation and annihilation.