Defect microstructure and deformation behavior of V-Ti-Cr-Si-Al-Y alloy irradiated in ATR

Low-temperature irradiation performance of vanadium alloys, especially afte r neutron irradiation below 400 degreesC, is a major concern. Defect micros tructures and deformation behavior of V-Ti-Cr type alloys containing small amounts of Si, Al and Y after neutron irradiation below 400 degreesC were s tudied. Neutron irradiation was conducted in the advanced test reactor (ATR ) to fluences of 0.7-4.7 displacements per atom (dpa) at temperatures from 141 degreesC to 293 degreesC. A large amount of hardening was observed in t he specimens irradiated at 290 degreesC or below, which corresponded to a h igh density of small dislocation loops. The density and the size of loops d epended on the irradiation temperature and the preirradiation annealing tem perature. The loops in the specimen annealed at 900 degreesC had a lower de nsity and a larger size than those annealed at 1000 degreesC and 1100 degre esC. The specimen annealed at 900 degreesC showed very small hardening and retained good work-hardening capability after irradiation at 290 degreesC. (C) 2000 Elsevier Science B.V. All rights reserved.