Effect of the bake-out regime on the recovery of properties of copper-based alloys and copper/steel joints

Copper alloys for ITER are characterized by rather strong radiation hardening and embrittlement at low irradiation temperatures of 80–200 °C. To reduce this effect it was proposed, with a certain dose attained, to use a special series annealing conditions at temperatures exceeding the operational temperatures. The report presents the results of an investigation into the effect of different annealing conditions, i.e. 300 °C – 10 h, 350 °C – 10 h and 400 °C – 10 h, on the recovery of properties (tensile and electrical conductivity) of copper-based alloys and copper/steel joints irradiated up to doses of 0.4 and 2 dpa at 150 °C. The results demonstrated that annealing helps to recover the mechanical properties of GlidCopAl25 IG alloy and joints. By comparison, the electric conductivity of the irradiated samples is only partially recovered. The conclusion is made that the bake-out regime allows for an effective recovery of ductile properties of copper alloys irradiated at low (150 °C) temperatures and, to somewhat lesser degree, the copper/steel joints.