Radiation embrittlement of low-alloyed Mo alloys

The influence of irradiation in the BOR-60 reactor at 250-1020 degrees C up to fluences 0.013-7.6 x 10(26) n/m(2) (E > 0.1 MeV) on the mechanical properties of a number of low-alloyed Mo alloys has been studied. Zr, Ti, Ru, B, C were used as alloying elements. Significant radiation strengthening and embrittlement of all the allays investigated took place during the course of irradiation. According to tension lest results, the brittle-ductile transition temperature, T-k, was 600-700 degrees C. Under comparable irradiation conditions, alloying had no substantial effect on the extent of irradiation embrittlement, since it did not prevent the radiation defect formation causing strengthening and, therefore, embrittlement. It was assumed that improvement of the Mo radiation resistance could be only obtained by high alloying with such elements as rhenium.