Abstract
This paper describes the crystal grain size effect of an aluminum alloy analyzed by a polycrystal plasticity FEM code the present authors have been developing. In order to analyze the crystal grain size effect, the code was modified to implement a crystal grain size effect in the initial critical resolved shear stress. The results showed that the smaller the crystal grain size, the higher the 0.2% proof stress. The relationship of calculated 0.2% proof stress to inverse square root of crystal grain size was represented by a single straight line, known as the Hall-Petch relation. The results revealed that the 0.2% proof stress was remarkably affected by grain size but that the work hardening behavior was not. It was conclude that the work hardening behavior was affected more by crystal orientation difference which can enhance the generation of dislocations.
