Diffusion bonding of copper alloy to nickel-based superalloy: effect of heat treatment on the microstructure and mechanical properties of the joints

Successful joining of heat conducting materials, to high-temperature components is significant importance for management in nuclear power plants and liquid propellant launch vehicles. Solid-state processes are considered such dissimilar materials. Diffusion bonding a copper alloy (C18150) Ni-based superalloy (GH4169) was investigated this work. The trials at 900°C 60 min under constant 10 MPa pressure led formation sound joints free from intermetallic, pores, voids discontinuities. Conventional tensile testing the failure within away joint. Due softening during process, maximum strength as-bonded only 48% its as-received strength. Post-bonding solution treatment 960°C followed by ageing 450°C 3.5 h, restored up 77%.