Abstract
The roles of grain boundaries in the plastic deformation of hexagonal close packed metals are not still clear despite of its importance, especially, for sufficiently small size of grains. In this work, we performed molecular dynamics simulations of uniaxial deformation tests of magnesium bicrystals with [1^^-100] symmetric tilt grain boundaries. We observed that not only the yield stress but also the active deformation mode itself is sensitively dependent on the misorientation angle of the bicrystal and the loading direction. In particular, ease of nucleation of basal dislocations from grain boundaries could be qualitatively explained by dependence of the grain boundary energy on the misorientation angle.
