EFFECT OF NEUTRON-IRRADIATION ON MICROSTRUCTURE AND TENSILE PROPERTIES OF TZM AND MO-5-PERCENT RE ALLOYS

The response of two molybdenum alloys (e.g. TZM and Mo-5% Re) to fissi on neutron irradiation has been investigated. These alloys were irradi ated in the DR-3 reactor at Riso National Laboratory with a flux of si milar to 2.5 x 10(17) n/m(2)/s (E > 1 MeV) at similar to 320 and 373 K to a fluence level of similar to 1.5 x 10(24) n/m(2) (E > 1 MeV), cor responding to similar to 0.16 dpa (NRT). The microstructure of these m aterials was investigated before and after irradiation. Both unirradia ted and irradiated specimens of the two alloys were tensile tested at similar to 295 and 373 K. The fracture surfaces of both alloys in unir radiated as well as irradiated conditions were investigated by scannin g electron microscopy. The main conclusion of the present investigatio n is that even this low dose irradiation causes a tremendous increase in tensile strength and a drastic decrease in elongation.