On the Formation and Stability of Two Misfit Dislocations in the Cu-γFe System

On growth beyond a critical size coherent precipitates become semicoherent by the formation of an interfacial misfit edge dislocation loop. On further growth of the precipitate, the interface progressively loses its coherency by the formation of additional dislocation loops. The current investigation pertains to the energetic feasibility of two dislocation loops. Finite element simulations are performed to simulate the stress state of the semicoherent precipitate and to compute the radius of the precipitate at which two symmetrically positioned dislocation loops become energetically favourable. Aspects regarding the stability of the loops are also explored using the simulations. Cu-γFe system is used as a model system to illustrate the methodology and to capture the essential aspects of the process.