RECENT ADVANCES IN THE UNDERSTANDING OF DAMAGE PRODUCTION AND ITS CONSEQUENCES ON VOID SWELLING, IRRADIATION CREEP AND GROWTH

The consequences of displacement damage produced by energetic particle s on physical and mechanical properties of metals and alloys have been investigated both experimentally and theoretically for several decade s. Over the years, a number of theoretical models have been proposed t o rationalize the rate and magnitude of defect accumulation under diff erent irradiation conditions, In recent years, significant advances ha ve been made in understanding the nature of the damage produced in thi s form of multi-displacement cascades. The new knowledge regarding the intra-cascade recombination and clustering of self-interstitial atoms and vacancies during the cooling-down phase of cascades makes it nece ssary to re-examine the appropriateness of the available models for de scribing the accumulation of damage under cascade damage conditions. I n this paper, recent advances in the understanding of damage productio n and its consequences are reviewed. A historic perspective is adopted . A comprehensive analysis of the effects of temperature, dose rate an d particle type on multi-phenomena (swelling, creep, growth, microstru cture evolution, RED, RIS) is presented to discuss the strength and we akness of various models, as they have evolved with the understanding of the damage processes. It has been shown that the irradiation damage modeling has progressed from the standard rate theory model to the BE K model to the production bias model with an increasing degree of soph istication as increasingly more realistic features of the irradiation damage production process were incorporated. It is shown that the newl y proposed production bias model uniquely includes the necessary featu res of cascade damage production in its treatment of the damage accumu lation.