By using atomistic simulations of dislocation motion in Ni and Ni-Au alloys, a detailed study was made of the mobility function as a function of stress, temperature and composition. The results were analyzed in terms of analytical models of phonon radiation and their selection rules for phonon excitation. Remarkable agreement was found between the location of the cusps in the σ-v relationship, and the velocity of waves propagating in the direction of dislocation motion. Three regimes of dissipation were identified whose boundaries were determined essentially by the direction of motion of the dislocation, rather than by its screw or edge character.

Moving Dislocations in Disordered Alloys - Connecting Continuum and Discrete Models with Atomistic Simulations. J.Marian, A.Caro: Physical Review B, 2006, 74[2], 024113 (12pp)