Molecular Dynamics Simulation of the Variation in the Microstructure of a Polycrystalline Material under Tensile Load

Molecular dynamics simulations were carried out to investigate the change in the crystal orientation of polycrystalline materials placed under an external load. Two models were prepared, both comprising four grains but with different grain arrangements. Each grain had a face-centered cubic structure with (001) face on the x-y plane, whereas each grain had a different rotation of orientation around the z -axis. A tensile load was applied by extending the edge length in the y direction while the other directions were kept stress-free. As a result, a significant change in the microstructure was observed, with changes in both crystal orientation and shape along with the formation of subgrains. The structure and direction of the grain boundary against the external load were also found to affect the change in the microstructure.