Molecular dynamics and first-principles study of grain boundary sliding in metals

抄録

Grain boundary sliding in various grain boundaries (pure, with segregation, and heterophase boundary) was investigated with molecular dynamics simulations and first-principles calculations from the atomic viewpoints. In the pure and segregated grain boundaries which have same grain boundary structure, the behavior of atomic movement during the sliding is same, and there was no correlation between the sliding rate and the grain boundary energy. First-principles calculations revealed that the sliding rate calculated by the molecular dynamics simulations increases with decreasing minimum charge density at the bond critical point in the grain boundary. In the heterophase boundary, the atomic movement was different from the pure and segregated grain boundaries according to the disordered grain boundary structure. Thus, the sliding rate depends on atomic movement enhanced by the defect structure at grain boundaries.