Slip-assisted twin growth in hexagonal close-packed metals

We study two possible twin growth mechanisms in hexagonal close-packed (hcp) metals: a slip-assisted one, based on dislocation reactions at twin interfaces, and a slip-independent one, based on the direct activation of twin dislocations. A twin thickening rate law is developed to estimate the contribution of slip dislocations to twin growth in hcp crystals. Application of the model to Mg single crystals, and comparison with experimental data, suggests that {101¯2} twin thickening proceeds independently of slip.