Influence of neutron irradiation on the mechanical properties of vanadium alloys

The influence of neutron irradiation on the mechanical properties of vanadium and the alloys V-10.6 Ti and V-10 Ti-6 Cr-0.05 Zr is investigated. Alloy samples are irradiated in the pile of a BOR-60 reactor to a fluence of (0.8-1).10(22) cm(-2) (E > 0.1 MeV) at 350 degrees C. The results show that the irradiation of vanadium and its alloys in these conditions leads to insignificant (less than 0.1%) swelling but changes their mechanical properties (strength and plasticity). The radiational strengthening is greatest for pure vanadium and least for the alloy V-10.6 Ti. Adding chromium to the alloy reduces the positive effect of titanium and leads to low-temperature radiational embrittlement in the range 20-100 degrees C. As shown by electron-microscope investigation, the change in mechanical properties of the alloys after irradiation is associated with the formation of a dislocational structure and with radiation-stimulated segregation.