Core properties and motion of dislocations in NiAl

Abstract

Dislocation core structures of 〈100〉, 〈110〉 and 〈111〉 dislocations in NiAl have been studied by molecular static calculations using an embedded atom potential. The response of dislocation cores to applied homogeneous shear stresses is investigated and the Peierls stresses of straight dislocations having edge, screw and mixed character is determined. The results are in many details in excellent agreement with experimental observations. The motion of dislocations in single crystals oriented for hard slip is discussed in a simple line-tension model.