Multiscale modeling of radiation hardening

Abstract

All materials used in nuclear reactors experience radiation hardening, thus altering significantly their mechanical behavior. Despite the large efforts made by the scientific community to correctly predict the radiation effects on nuclear materials, many difficulties persist in modeling radiation defects. Although radiation hardening is responsible for macroscopic consequences such as embrittlement, its fundamental mechanisms prevail at the atomic scale. The fast development of simulation techniques, especially atomistic simulations, helped in exploring many features of dislocation interactions with radiation-induced defects. For a long time, the obtained results were used to validate theoretical models and to qualitatively explain and rationalize experimental observations. More recently, with the ubiquity of simulation results and techniques at different scales, quantitative physically based predictions of the mechanical behavior became a realistic objective. Efforts were made to couple simulation results at different scales through the development of scale transition methods and the construction of constitutive equations of the local mechanical behavior. The objective of this chapter is to trace the evolution and progress of this strategy, thus enabling the construction of a chain of physical knowledge across the scales. Details of simulations techniques and methods are not presented. We emphasize on basic achievements of simulations and on the treatment of results with the aim to bridge the different scales of interest for the mechanical behavior.