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

摘要

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 preexisting twin.