The effect of brazing cycle simulation on radiation embrittlement of ph copper alloys irradiated in SM-2 reactor up to 5dpa

Abstract

Abstract The paper presents the results of investigation into the radiation resistance of Precipitation hardened (PH) copper alloys of Cu-Cr-Zr and Cu-2Be type irradiated up to 5 dpa in the SM-2 reactor at T in = 120°C and 300°C. The PH copper alloys were irradiated in two states: 1. optimized state - quenching at 900°C, 4h ageing at 480°C; 2. after simulation of brazing cycle at 850°C - 1 h, slow cooling. The low-temperature embrittlement causes the Cu-Cr-Zr alloy to strengthen and embrittle. Annealed samples of these alloys are characterized by a lower yield strength and a high plasticity in the irradiated state. The Cu-2Be alloy after low-temperature irra-diation is brittle both in the optimized state and after annealing. Irradiation at 300°C results in plastification and partial softening of the alloys in both states. The conclusion is made that after thermal brazing cycle Cu-Cr-Zr type PH copper alloys have a satisfactory radiation resistance in the irradiation temperature range of 120-300°C up to ir...