A discrete-lattice kinetic Monte Carlo model was developed in order to simulate the motion of an edge dislocation in the presence of interacting diffusing solute atoms which misfitted the matrix. The simulation self-consistently determined the solute concentration profile in 2 dimensions, as well as the associated dislocation velocity. The solute segregation profile around the moving dislocation was characterized, at low velocities, by a condensed solute cloud near to, and on one side of, the dislocation core plus a region which was depleted of solute on the opposite side - and a diffuse solute (Cottrell) atmosphere further from the core. No condensed solute cloud formed at high velocities. The relationship between the dislocation velocity and the applied stress included a low-velocity solute-drag branch, and a high-velocity branch; typified by the absence of a solute cloud, but with occasional solute-trapping. At intermediate velocities, the dislocation jumped stochastically between these 2 branches.

Dislocation Motion in the Presence of Diffusing Solutes - a Computer Simulation Study. Y.Wang, D.J.Srolovitz, J.M.Rickman, R.Lesar: Acta Materialia, 2000, 48[9], 2163-75