On the primary creep of Ni3Al

Abstract

The primary creep stage in single-crystal Ni3Al (1 at.% Ta) at an intermediate temperature of 520°C and at a stress of 550 MPa has been investigated. It is found that edge superdislocations in the [123] orientation dissociate on the octahedral plane while their counterparts in the [1 1 12]orientation, which is about 7° off the [001]orientation, climb-dissociate subject to the same duration of creep (7 h). It is concluded that the climb-dissociation leads to the end of primary creep and that it occurs after the edge dislocations are halted by forest interactions.