Deformation induced FCC lamellae and their interaction in commercial pure Ti

Abstract Titanium with hexagonal close-packed (hcp) structure can undergo phase transformation to face-centered cubic (fcc) structure under mechanical straining at room temperature. In this work, we identified two orientation relationships (ORs) between fcc phase and hcp matrix in commercial pure Ti, i.e., P-type OR [ 1 ¯ 2 1 ¯ 0]hcp||[1 1 ¯ 0]fcc and (10 1 ¯ 0)hcp||(110)fcc, and B-type OR [ 1 ¯ 2 1 ¯ 0]hcp||[1 1 ¯ 0]fcc and (0001)hcp||( 1 ¯ 1 ¯ 1)fcc. The P-type interface is flat while the B-type interface is stepped, which are ascribed to the pure-shuffle mechanism and the partial gliding mechanism, respectively. Most intriguingly, the B-type fcc lamella can penetrate the P-type fcc lamella through gliding of the dislocation with Burgers vector ½[110] on (001) fcc plane.