Abstract
•321 stainless steel and Inconel 738 was diffusion bonded using 54Ag-40Cu-5.0Zn-1.0Ni powder-mixture as interlayer.•Effect of holding pressure on metallurgical and mechanical properties of the joint was investigated.•The increase in pressure improves the interatomic diffusion and facilitates the formation of a more uniform and wider diffusion affected zone.•An increase in the holding pressure increases the shear strength of the diffusion brazed joints.
The application of 54Ag-40Cu-5.0Zn-1.0Ni powder-mixture interlayer in the diffusion-brazing of Inconel 738 and AISI 321 stainless steel was investigated under a holding pressure variance (1 and 2 MPa). The resultant microstructure, shear strength, and fracture of the brazed joints were investigated. An increase in the holding pressure facilitates better atomic diffusion, uniform thermally-induced reaction layer, and improves the shear strength of the brazed joints. The interfacial reaction layers are made of Cu-rich and Ag-rich phases irrespective of the difference in the holding pressure. Thus, a higher bonding/holding pressure is recommended for the diffusion brazing of Inconel and stainless steels when the brazing medium is a powder mixture.