Atomic simulations of twist grain boundary structures and deformation behaviors in aluminum

The structures and behaviors of grain boundaries (GBs) have profound effects on the mechanical properties of polycrystalline materials. In this paper, twist GBs in aluminum were investigated with molecular dynamic simulations to reveal their atomic structures, energy and interactions with dislocations. One hundred twenty-six twist GBs were studied, and the energy of all these twist GBs were calculated. The result indicates that < 001 > and < 111 > twist GBs have lower energy than < 101 > twist GBs because of their higher interplanar spacing. In addition, 12 types of < 001 > twist GBs in aluminum were chosen to explore the deformation behaviors. Low angle twist GBs with high density of network structures can resist greater tension because mutually hindering behaviors between partial dislocations increase the twist GB strength. (C) 2017 Author(s).