Investigation on effects of process parameters on microstructure and mechanical properties of GH5188 direct diffusion bonding

The process of direct diffusion bonding using GH5188 superalloy was investigated. The paper revealed that the bonding interface exhibited varying degrees of grain boundary migration as temperature increased, time extended, and pressure intensified. Furthermore, appropriate bonding pressure effectively promoted recrystallization in the joint, thereby enhancing its mechanical properties. The optimal joint was achieved at 1180 °C/60 min/15 MPa parameter, with yield tensile strength (YTS) reaching 467.7 MPa, ultimate tensile strength (UTS) reaching 998.2 MPa, elongation (EL) reaching 73.6 %, axial deformation at this parameter was measured at 2.2 %, with fracture surfaces located at base metal (BM) area, where numerous ductile dimple structures were observed.