Microstructural evolution in V-alloys following upward and downward temperature changes were examined. The alloys were irradiated in a high-fluence irradiation facility, using either a constant temperature of 500C or step-wise temperature sequences (350/500C, 400/500C, 450/500C, 500/550C, 350/500/350) up to 0.5 or 0.75dpa. Small dislocation loops were observed after the 350/500C and 400/500C temperature-change irradiations. The density of these dislocation loops decreased with pre-irradiation temperature. Following 450/500C irradiation, the microstructure indicated that the initial temperature was in the regime where defect growth mainly occurred. In the case of downward temperature changes, microstructures which were coarser than those at higher temperatures were observed.

Effects of Temperature Change on the Microstructural Evolution of Vanadium Alloys under Ion Irradiation. N.Nita, T.Iwai, K.Fukumoto, H.Matsui: Journal of Nuclear Materials, 2000, 283-287, 291-6