Microstructures and mechanical properties of electron beam welded CuCrZr/Inconel/316L tube-to-tube junctions for WEST project

•Macro- and micro-segregation were observed in electron beam welded CuCrZr/Inconel 625 joints.•Post-weld aging stimulated the formation of Nb/Mo-rich networks and increments of micro-hardness in Inconel-rich irregular islands.•Both the as-welded and aged specimens passed 10,000 cycles of rotary bending fatigue testing under a strain amplitude of 0.1%.•Aging shifted the weakest point of CuCrZr slightly away from the Inconel/CuCrZr weld.