Microstructure of vanadium alloys during ion irradiation with stepwise change of temperature

To understand the influence of a stepwise change of irradiation temperature on pure vanadium and vanadium alloys, ion irradiation were performed at 47 3 K to 0.25 dpa and 873 K to 0.5 dpa. In pure vanadium and V-5Cr alloy, shr inkage of interstitial type loops was prominent during irradiation at 873 K . These results were explained by the appearance of a vacancy rich conditio n during the successive irradiation at 873 K. In Ti-containing alloys (V-5T i V-4Cr-4Ti), on the other hand, dissociation of vacancy loops leads to the shrinkage of interstitial type loops and the formation of Ti-enriched prec ipitates. (C) 2000 Elsevier Science B.V. All rights reserved.