The effects of dislocation climb upon the mechanisms by which dislocations by-passed particles were examined. The analysis was based upon 3-dimensional level-set dislocation dynamics simulations that included all elastic interactions, dislocation glide, cross-slip and climb, and particles that were either impenetrable or penetrable and with or without misfit. When the particle misfitted with respect to the matrix, dislocation migration was strongly influenced by the elastic fields created by the misfit. An edge dislocation tended to climb towards the top or the bottom of the particle, and could remain there if the stress was not too large. A screw dislocation could wrap itself around the particle several times; creating a helical dislocation structure under low applied stresses. If the stress was increased, these helices broke up into an array of loops. Without misfit, climb invariably lowered the threshold stress for particle by-passing. However, in the misfit case, climb could also lead to more stable dislocation structures and thus increase the threshold stress.

Dislocation Climb Effects on Particle Bypass Mechanisms. Y.Xiang, D.J.Srolovitz: Philosophical Magazine, 2006, 86[25-26], 3937-57