The effect of neutron irradiation on the mechanical properties of precipitation hardened copper alloys

The effects of neutron irradiation on strength and ductility properties of precipitation hardened (PH) copper alloys are discussed. The analysis is based on the experimental study of radiation damage of PH alloys irradiated in the mixed spectrum reactor SM-2 to fluences of 3.7-5.5 X 10(25) n/m(2) (E > 0.1 MeV), corresponding to NRT displacement dose levels of 2.6-3.8 dpa. At irradiation temperatures of 100-285 degrees C the processes of radiation hardening and reduction in the uniform elongation are the major effects. Irradiation at temperatures higher than 300 degrees C causes a dramatic softening and improvement in uniform elongation of the Cu-Cr-Zr and Cu-Cr-Zr-Mg alloys. The threshold softening temperature for the PH alloys is shown to be about 300 degrees C at a dose of 4.5 X 10(25) n/m(2) (E > 0.1 MeV). The effect of the irradiation dose and temperature on the shift of the threshold temperature of PH copper-alloys softening is also considered. (C) 1997 Elsevier Science B.V.