A theoretical approach to combined hardening mechanisms in crystal plasticity

Abstract

Hardening of polycrystals is often described by phenomenological models such as the one by Kocks and Mecking (KM). With the Taylor equation, it describes strain hardening in single-phased materials. Grain boundary and precipitation hardening are then included by adding empirical corrections. Here, the theoretical bases of KM-will be explored. The Taylor equation is obtained from an evolution equation for shear stress as a function of dislocation density, which can be modified to include precipitates. Dynamic annihilation and the grain size effect will be analysed from a probabilistic analysis of the slip length used in KM, to provide a theoretical basis for combined hardening mechanisms in alloys.