A physically based yield criterion II. Incorporation of Hall Petch effect and resistance due to thermally activated dislocation glide

Abstract

The anelastic model developed in part I of this paper [1] is extended to incorporate the Hall-Petch effect and the thermally activated pre yield phenomena that were revealed in the stress cycling experiments The yield criterion developed in [1] is tested by application to Hall-Petch experiments and measurements of the yield stress as a function of strain rate and temperature. The results of the strain rate/temperature experiments support the conclusion that reversible dislocation glide occurs before yield and massive dislocation multiplication. The model is substantiated by analysis of parameters pertaining to the initial dislocation structure viz. the average initial dislocation segment length and density computed from experimental data by application of the model equations.