Stress-induced phase transformation and phase boundary sliding in Ti: An atomically resolved in-situ analysis

In-situ tensile experiments on pure Ti were performed in a transmission electron microscope at room temperature. The dynamic process of stress-induced hexagonal closed-packed (hcp) to face-centered cu-bic (fcc) structural transformation ahead of a crack tip was captured at the atomic level. Intriguingly, a sliding behavior of the ensuing (0 0 01)hcp/(11 over line 1 )fcc phase boundary was observed to further accommodate the plastic deformation until crack initiation. The sliding was accomplished via the successive conserva-tive glide of extended dislocations along the (0 0 01)hcp/(11 over line 1 )fcc phase boundary. A molecular dynamics simulation was carried out to corroborate the experiments and the results confirm the new dislocation -mediated sliding mechanism.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.