Solid-State Joining of Dissimilar Ni-Based Superalloys via Field-Assisted Sintering Technology for Turbine Applications

Friction welding or electron/laser beam welding of nickel superalloys compromises the microstructure with localized melting and heat-affected zones (HAZ). In this work, Field-Assisted Sintering Technology (FAST) is studied as an alternative method for solid-state diffusion bonding of superalloys CM247LC and Inconel 718. Bonding microstructures and room-temperature tensile strengths are evaluated. Preliminary results suggest that FAST bonding leads to an interface with a compositional gradient without producing a HAZ and without losing tensile strength.