It was noted that dislocations in the crystallites of nanocrystalline materials formed special configurations, and the dislocation density sharply decreased. A model was proposed to account for the effects of defects, in the grain boundaries of nanocrystalline materials, upon the dislocation stability and configuration in the crystallites. Based on the fact that the grain boundaries of such materials contained a large number of vacancies and vacancy clusters, a 1/x3 law for the stress field induced by the vacancies and the vacancy clusters was considered. The region of dislocation stability in the crystallites was estimated, and the dislocation configurations in the crystallites were considered. The theoretical results explained well the experimental data.

Dislocation Stability and Configuration in the Crystallites of Nanocrystalline Materials. W.Qin, Y.W.Du, Z.H.Chen, W.L.Gao: Journal of Alloys and Compounds, 2002, 337[1-2], 168-71