A 3D multiscale crystal plasticity simulation on ultrafine-graining of FCC polycrystal based on dislocation patterning

Aoyagi, Yoshiteru; Shizawa, Kazuyuki*

Ultrafine-grained metals whose grain size is less than one micron have attracted interest as high strength materials. In this study, in order to predict spontaneous dislocation patterning, generation rate of mobile dislocations is newly introduced into reaction-diffusion model. Information of deformation is related with the reference dislocation density through the generation rate depending on stress and activity of other slip system. In addition, carrying out pseudo-three-dimensional FE simulation for severe compression of FCC polycrystal using a multiscale crystal plasticity model based both on dislocation patterning and accumulation of geometrically necessary dislocations, we predict numerically the processes of ultrafine-graining of FCC crystal. We investigate comprehensively the effect of dislocation behaviors on the processes of ultrafine-graining.