The interfacial misfit dislocation networks in a DS casting Ni 3Al base alloy IC6

Abstract

The interfacial misfit dislocation networks (IMDN) in an unidirectionally-solidified (DS) casting Ni 3Al base alloy IC6 have been investigated by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and stress-field analysis. It is found that the IMDN is composed of the edge dislocations with the Burgers vectors a 2 〈110〉 and a〈100〉 on the {001} γ/γ' interface. The effective stress field is within the limit of 10–20 nm. The density of the IMDNs is around 15–20 nm/N, depending on the heat-treatment conditions and deformation conditions of the specimen. The existence of the IMDNs effectively exhibits the motion of moving dislocations during deformation.