Interface morphology and formation mechanism of dissimilar steel joint with transient liquid-phase bonding

The dissimilar steel pipes were joined by transient liquid-phase two-step heating bonding process with FeNiCrSiB amorphous foil in argon atmosphere.The microstructure and mechanical properties of the bonding joint were studied.The interface morphology of the transient liquid-phase bonding joint was analyzed by laser confocal microscopy.The testing results indicated that the solidification of the liquid interlayer occurred on the substrate and the grains grew along a specific direction.A curved interfacial layer formed because a small amount of impurities distributed in the center of the weld.The short-term hightemperature heating of transient liquid-phase two-step heating bonding process can promote the melting of the substrate and epitaxial growth of the grains.