Investigation of crystal stress dependence on lattice orientation, loading direction, and grain interactions in a plastically deforming crystal embedded within a polycrystal aggregate

Understanding the behavior of deforming materials is essential for better designing innovative materials and identifying the behavior of materials in service. However, most engineering materials are polycrystalline and, due to the complex behavior of polycrystalline solids, the conduction of in-depth analyses has not been readily available. As techniques such as the high-energy X-ray synchrotron experiment have become available, findings from simulations can now be supported by real observation and vise versa. Using the synergic tool of combining the experiment and the simulation, it has been shown that crystal stress evolution is dependent upon crystal orientation. In this research, the crystal stress evolution pattern at a single crystal during plastic flow is investigated using simulated data from finite element analyses. By investigating the crystal stress evolution of specific crystal orientations, the influence of a crystal orientation and the arrangement of neighboring grains on the crystal stress evolution is analyzed. It is confirmed that the crystal stress direction tends to move closer to a vertex of a single crystal yield surface, but the coaxiality is influenced by the grain orientations and spatial topology of neighboring grains. It is also shown that the spread of crystal stress values within a crystal is strongly dependent on the homogeneity of active polyslip systems, which is determined by the loading direction as well as the grain orientation.