The interactions of 1/6<112]{111}γ twinning dislocations with {111}γ/{¯1¯1¯1}T coherent twin interfaces, which intersected along <101]γ (30°-type) and <110]γ (edge-type) directions in duplex alloys after room-temperature tensile deformation, were investigated by using transmission electron microscopy. The dislocation reactions which were involved in each type of interaction that described the slip transfer processes were identified by matching experimental and computed images. The slip transfer of incoming 30°-type 1/6<112]{111}γ dislocations across the {111}γ/{¯1¯1¯1}T coherent twin interface occurred via the transmission of ½<110]{111}T slip dislocations and 1/6<112]{111}T twinning dislocations into the twinned γ phase; in association with the motion of 1/6<112]{111}γ-T twinning dislocations in the plane of the coherent twin interface. In the case of interactions involving incoming edge-type 1/6<112]{111}γ dislocations with {111}γ/{¯1¯1¯1}T coherent twin interfaces, transfer occurred via ½<110]{001)T slip dislocations which were transmitted into the twinned γ phase; together with ½<110]{001)γ slip dislocations which were 'reflected' back into the matrix γ phase. Under some conditions, this was also coupled with the motion of 1/6<112]{111}γ-T twinning dislocations in the plane of the coherent twin interface.

Slip Transfer of Deformation Twins in Duplex γ-Based Ti-Al Alloys - I. Transfer Across γ-γ Coherent Twin Interfaces. M.A.Gibson, C.T.Forwood: Philosophical Magazine A, 2000, 80[12], 2747-83