Deformation induced FCC lamellae and their interaction in commercial pure Ti

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) over bar2 (1) over bar0]hcp parallel to[1 (1) over bar0]fcc and (10 (1) over bar0)hcp parallel to(110)fcc, and B-type OR[(1) over bar2 (1) over bar0]hcp parallel to[1 (1) over bar0]fcc and (0001)hcp parallel to((1) over bar(1) over bar1)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 1/2[110] on (001)(fcc) plane. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.