Elastic‐Modulus Effect in the Interaction of Point Defects with Dislocation Ribbons

摘要

The interaction energy due to modulus differences of point defects, such as solute atoms and vacancies, with dislocations is derived, using Eshelby''s theory of interaction energy of an elastic inhomogeneity in the presence of applied stress field. It is shown that the interaction may be attractive or repulsive depending on the ratio of shear moduli, μi and μ, of the point defects and solvent atoms, respectively, and the parameter ϵ=[(1+νi) / (1+ν)]/[(1-2νi) / (1-2ν)], where νi and ν are Poisson''s ratios of point defects and solvent atoms, respectively. The energy profile for the case of screw‐dislocation ribbons differs remarkably from that of edge‐dislocation ribbons. The result obtained can be used to account for the annealing‐out of the stacking fault of a dislocation ribbon, and the contribution to segregation or desegregation of solute atoms at the stacking fault.