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

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-irr = 120 degrees C and 300 degrees C. The PH copper alloys were irradiated in two states: 1. optimized state - quenching at 900 degrees C, 4h ageing at 480 degrees C; 2. after simulation of brazing cycle at 850 degrees C - Ih, dow 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 ahoy after low-temperature irradiation is brittle both in the optimized state and after annealing. Irradiation at 300 degrees 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 degrees C up to irradiation doses of 5 dpa.