Diffusion Bonding of FGH 98 and CoCrNi-Based Medium-Entropy Alloy: Microstructure Evolution and Mechanical Tests

The superalloy FGH98 was successfully diffusion bonded (DB) with medium-entropy alloy (MEA) Al3Ti3(CrCoNi)94 using pure Ni as the interlayer at a temperature range of 1050–1170 °C for 1 h under 5 MPa. microstructure and mechanical properties joints were investigated. bonding seam composed an zone (IZ) two diffusion-affected zones (DAZ). IZ DAZ beside consisted cubic Ni3(TiAl)-type ?? phases due to Ti Al atoms. Meanwhile, adjacent MEA spherical phases. Both different morphology kept coherent relationship matrix. Moreover, increase led phase transform from sphere cube. Due strengthening effect mass distributed evenly in FGH98, microhardness Young’s modulus these higher than that near MEA. maximum shear strength DB joint, 592 MPa, achieved joint by 1150 °C, which typical ductile fracture feature confirmed dimples.