Modeling the generation equilibrium, and emission of dislocations at elastically misfitted particles

The generation, equilibrium, and emission of dislocations from an elastical ly mismatched particle-matrix interface under the combined effects of therm al and mechanical loading have been studied. Energy considerations are used to compute the generation, equilibrium, and instability conditions, and fo rce balance is used to find the equilibrated loop shape. When the mismatch strain exceeds the generation limit, which is particle size dependent, the generation of dislocations lowers the system energy, and a stable dislocati on loop segment will be generated and bulge out from the particle-matrix in terface. Upon reaching instability, also particle size dependent, the dislo cation will be emitted from the particle. Analytic expressions describing t he generation, equilibrium, and instability are derived. A dislocation gene ration mechanism map is obtained for the analysis and design of particle-re inforced composites under thermomechanical loading. (C) 1998 Acta Metallurg ica me. Published by Elsevier Science Ltd. All rights reserved.