On the structure and mobility of dislocations in NiAl

Dislocation core structures of 〈100〉, 〈110〉 and 〈111〉 dislocations in NiAl have been studied by molecular statics calculations using a new many-body 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 determined. The results are generally in good agreement with experimental observations. Finally, the mobility of dislocations in single crystals oriented for hard slip is discussed in a simple line-tension model.