Improvement in post-irradiation ductility of neutron irradiated V-Ti-Cr-Si-Al-Y alloy and the role of interstitial impurities

An attempt to maintain the uniform elongation (UE) of vanadium alloys after irradiation is described. Neutron irradiation was carried out at Advanced Test Reactor (ATR) and at Experimental Breeder Reactor II (EBR-II) to the f luence of Il dpa. The UE was maintained about 6% after irradiation at 388 d egreesC. The UE became negligible after irradiation below 300 degreesC for the alloy annealed at 1000 degreesC and 1100 degreesC. The specimens anneal ed at 900 degreesC and 700 degreesC still showed relatively large UE after such low-temperature irradiation. Comparing with the results in literature, it is proposed that oxygen concentration should be kept below 200 ppm to m aintain the UE after irradiation below 400 degreesC. The control of interst itial impurities, especially oxygen in solution, was important to maintain the UE of the alloy. (C) 2000 Elsevier Science B.V. All rights reserved.