Molecular dynamics study on void collapse in single crystal hcp-Ti under hydrostatic compression

Abstract Molecular dynamics simulations were performed to investigate the void collapse in single crystal hcp-Ti under hydrostatic compression. The principal mechanisms of deformation are identified. In the early stage, the dislocations nucleate at the intersections of facets, four slip systems ( 1 / 3 1 1 2 ¯ 0 > { 1 1 ¯ 0 0 } , 1 / 3 1 1 2 ¯ 0 > { 1 1 ¯ 0 1 } , 1 / 3 1 1 2 ¯ 3 ¯ > { 1 1 ¯ 0 1 } and 1 / 3 1 1 2 ¯ 0 > { 0 0 0 2 } ) are activated. As deformation continues, non-planar loops form, and the perfect dislocation decomposition occurs only on the basal plane. Effects of void sizes on mechanical respond are also investigated, and the results show that the stress decreases as the initial void size increases, while the dislocation density increases as the initial void size increases. What’s more, dislocation detachment occurs by chance.