Phase field modelling voids nucleation and growth in binary systems

TL;DR

This paper models void formation, nucleation, and growth in binary alloys under irradiation using phase field and rate theories, revealing how elastic interactions and composition changes lead to void super-lattice formation.

Contribution

It introduces a combined phase field and rate theory approach to simulate void dynamics in irradiated binary alloys, highlighting elastic effects and anisotropic precipitate formation.

Findings

Void formation driven by vacancy interactions and elastic deformation.

Void super-lattice formation due to elastic inhomogeneity.

Diffusion-controlled void growth with universal dynamics.

Abstract

We present a comprehensive study of voids formation, nucleation and growth in a prototype model of binary alloys subjected to irradiation by using a combined approach based on phase field and rate theories. It is shown that voids formation is caused by interaction of irradiation-produced vacancies through elastic deformation of a lattice and vacancy coupling with composition field of the alloy. Phase diagrams illustrating the formation of states related to solid solution, phase decomposition, and patterning are obtained. Formation of voids from supersaturated ensemble of vacancies is accompanied by composition rearrangement of alloy components. It was found that elastic inhomogeneity leading to the formation of anisotropic precipitates in an initially prepared binary alloy results in the formation of a void super-lattice under irradiation. It was shown that voids nucleate and grow with dose according to diffusion controlled precipitation processes, where universal dynamics of voids growth is revealed. Estimations of main quantitative and statistical characteristics of voids by using material parameters relevant to most of alloys and steels give good agreement with experimental observations.