On the migration of {3 3 2} 〈1 1 0〉 tilt grain boundary in bcc metals and further nucleation of {1 1 2} twin

a) Schematic of the upwards displacement of a {3 3 2} GB and the nucleation of a {1 1 2} twin at a GB dislocation. b) c) and d) Nucleation and growth of the twin due to the pileup of disconnections at both sites of the GB dislocation. e) and f) Growth of the twin due to the motion of the tip inside the grain.