Micro stress analysis of multi-phases polycrystalline metallic materials

This paper discusses a method to simulate the mechanical response of multi-phase microstructure for metallic materials. Multi-phase polycrystalline material is modeled as an ensemble of grains with different phases. Each grain has different shape and orientation. The response of the multi-phase polycrystal is the aggregate response of the constituent grains. The model is developed by combining Voronoi tessellation with MSC PATRAN/NASTRAN finite element analysis software. In each phase, grain size, shape and property orientation have been considered to study the micro-stress distribution in the model, and von Mises stress at the center of each grain has been found to be strongly correlated with the grain orientation and weakly correlated with grain size and shape. A stress analysis is performed on a representative volume element of Ti-6Al-4V as illustration to show the alpha-phase grain with hexagonal closed packed (HCP) structure and alpha+beta phase grain with needle-like colony structures interacting in this simulating model. The results show that the model compares favorably with other polycrystalline metallic material studies.