Observation of a[100] Dislocations in the γ′ Phase in a [011]-Oriented Nickel-Base Single Crystal Superalloy During High Temperature Creep

Superdislocation configurations in a [011]-oriented single crystal superalloy after creep at 1100 °C/150 MPa have been investigated. Besides a〈110〉 superdislocations, a[100] superdislocations are observed. TEM analysis shows that these a[100] superdislocations are pure edge dislocations and mainly lie on (100) plane with 〈011〉 directions. They form by the reactions of two matrix dislocations with different Burgers vectors, and they may move in a similar way to a〈100〉 dislocations in [001] specimens owing to the zero Schmid factors.