Using 3-dimensional discrete dislocation dynamics simulations, the effect of Y2O3 dispersoids upon the motion of dislocations in body-centred cubic single-crystal PM2000 was studied. The dispersoid distribution used was derived from experimental transmission electron microscopic observations of PM2000. As screw dislocations were predominant in the studied material, the behaviour of a single a/2(110)[1¯11] screw dislocation under shear loading in a distribution of spherical Y2O3 dispersoids was studied. The critical resolved shear stress, the minimum value of the external stress needed to move the dislocation through the obstacle field, was found to be only slightly lower than the experimentally determined value; revealing that dispersoids made the main hardening contributions.

Discrete Dislocation Dynamics Simulations of Dislocation Interactions with Y2O3 Particles in PM2000 Single Crystals. B.Bakó, D.Weygand, M.Samaras, J.Chen, M.A.Pouchon, P.Gumbsch, W.Hoffelner: Philosophical Magazine, 2007, 87[24], 3645-56