A new numerical dislocation climb model based upon incorporating the pipe diffusion theory of vacancies with three-dimensional discrete dislocation dynamics was developed. In this model it was proposed that the climb rate of dislocations was determined by the gradient of the vacancy concentration on the segment, but not by the mechanical climb force as traditionally believed. The nodal forces on discrete dislocation segments in discrete dislocation dynamics simulation were transferred to pipe diffusion theory to calculate the vacancy concentration gradient. This transfer establishes a bridge connecting the discrete dislocation dynamics and pipe diffusion theory. The model was highly efficient and accurate. As verifications, two typical climb-involved examples were predicted, e.g. the activation of a Bardeen–Herring source as well as the shrinkage and annihilation of prismatic loops. Finally, the model was applied to study the break-up process of an infinite edge dislocation dipole into prismatic loops. This coupling methodology provided a useful tool for intensively studying the evolution of dislocation microstructures at high temperatures.

Investigations of Pipe-Diffusion-Based Dislocation Climb by Discrete Dislocation Dynamics. Y.Gao, Z.Zhuang, Z.L.Liu, X.C.You, X.C.Zhao, Z.H.Zhang: International Journal of Plasticity, 2011, 27[7], 1055-71