The Peierls stress for 1/6<111> twinning dislocations and ½<111> perfect dislocations in a body-centered cubic structure was evaluated. The calculations were performed using the Peierls-Nabarro formalism. The Peierls stresses were determined from the migration energy of a twin boundary γtbm and the energy of an unstable stacking fault γus. The values of γtbm and γus were calculated using a set of generalized many-body interatomic potentials. The potentials were defined so as to ensure different stability of the body-centered cubic structure relative to other structures. It was shown that this approach provided realistic values of the Peierls stress. The values of the Peierls stress for 1/6<111> twinning dislocations were very sensitive to the model parameters, unlike those for ½<111> perfect dislocations.

Evaluation of the Peierls Stress for Boundary Dislocations. A.Ostapovets, V.Paidar: The Physics of Metals and Metallography, 2011, 111[3], 229-35