The properties of dislocations in B2 material were studied atomistically by using an embedded atom potential. The response of dislocation cores to applied homogeneous shear stresses was investigated, and the Peierls stresses of straight dislocations were determined. The results were often in excellent agreement with experimental observations. In particular, the behavior of (111) dislocations, their slip planes, cross-slip behavior and the limiting role of screw dislocations could be explained. Also, the appearance of {210} planes as secondary slip-planes for (100) dislocations could be rationalised. The interaction of dislocations with structural point defects was studied. A comparison with the known flow stress of off-stoichiometric NiAl showed that the individual point defects could not be responsible for the large increase in flow stress; thus suggesting that more complex defect structures might play an important role.

Atomistic Aspects of the Deformation of NiAl. P.Gumbsch, R.Schroll: Intermetallics, 1999, 7[3-4], 447-54