Twin-dislocation and twin–twin interactions during cyclic deformation of a nickel-base single crystal TMS-82 superalloy

•At the primary stage of thermomechanical fatigue cycling, deformation twins can grow smoothly.•When large amounts of dislocations are introduced, deformation twin can be hindered in varying degrees.•Tangled dislocations which emerge after a deformation twin has formed will not affect the morphology of a pre-existing twin.•If there are few dislocations around a pre-existing twin, a growing twin can pass through it smoothly.•If lots of dislocations pile up around the pre-existing twin, the growing twin will be stopped at the intersection site.

The characteristics of twin-dislocation and twin–twin interactions in a nickel-base single crystal TMS-82 superalloy have been investigated after thermomechanical fatigue (TMF) testing. The resistance for a growing twin increases significantly with the introduction of tangled dislocations. When there are few dislocations at the primary stage of TMF cycling, twinning dislocations can move straight or pass through a pre-existing twin smoothly. When there exist large amounts of dislocations during TMF process, a propagating twin will be hindered in varying degrees. Dislocations will not affect the morphology of a pre-existing twin.