Deformation-induced α₂/γ interfaces in a hot-deformed Ti-45Al-10Nb alloy

The structure change of α₂/γ interface in a Ti-45Al-10Nb alloy induced by hot deformation was investigated by conventional and high-resolution transmission electron microscopy. Two types of hot deformation induced special α₂/γ interfaces, coherent interfaces with high density of ledges and semi-coherent α₂/γ interfaces were found to be due to the absorption of mobile dislocations into the α₂/γ interface. For the misoriented semi-coherent α₂/γ interfaces, the densities of dislocation ledges increase with the misoriented angle between (111)_γ and (0001)_α2 planes, and 1/3[111] Frank partial dislocations were involved in the dislocation ledges. Formation mechanism of these deformation-induced 0:2/7 interfaces was discussed to be related to the role of 0:2/7 interfaces adjusting the deformation as a dislocation sink absorbing the slipping dislocations in the γ phase.