Impacts of damage production and accumulation on materials performance in irradiation environment

Aspects of generation of atomic displacements and surviving defect fractions and their sensitivity to recoil energy have been considered. These considerations show that the nature of the primary damage production plays a vital role in the evolution of the damage accumulation as well as mechanical properties. The problem of damage accumulation on a global scale still remains a theoretical challenge! A substantial amount of theoretical effort is required to develop a realistic model to describe the damage accumulation at low temperatures (<stage V) and to establish a reliable relationship between the damage accumulation, irradiation hardening and the loss of ductility. The recently developed production bias model together with one-dimensional glide of interstitial clusters produced in the cascades has been shown to describe the damage accumulation at temperatures above stage V for pure metals and needs to be extended to temperatures below stage V and to materials of practical interests. This requires, however, that the information regarding the effects of alloying elements and impurity atoms on the nature of the primary damage state are available from molecular dynamics and kinetic Monte Carlo type of simulations. (C) 1998 Elsevier Science B.V. All rights reserved.