Damage production, accumulation and materials performance in radiation environment

Abstract

Collisions of energetic projectile particles with host atoms produce atomic displacements in the target materials. Subsequently, some of these displacements are transformed into lattice defects and survive in the form of single defects and defect clusters. Depending on the ambient temperature, these defects and their clusters diffuse, interact, annihilate, segregate and accumulate in various forms and are responsible for the evolution of the irradiation-induced microstructure. Naturally, both physical and mechanical properties and thereby the performance and lifetime of target materials are likely to be determined by the nature and the magnitude of the accumulated defects and their spatial dispositions. A multitude of processes covering a variety of temporal and spatial scales contribute to the evolution of the global microstructure. Results of computer simulations as well as theoretical modelling describing some of these processes will be reviewed and discussed. The framework within which the influence of irradiation on void swelling, radiation hardening and loss of ductility can be treated will be discussed. It will be emphasized that the nature of displacement damage production plays an important role in the evolution of the global microstructure. Finally, a brief summary of the current status in the fields of computer simulations and theoretical modelling is presented in the form of concluding remarks.