TLP bonding of 316L stainless steel with amorphous interlayer alloys

The component and phase structure of interlayer alloys for TLP bonding of 316L stainless steel have been studied and the effect of interlayer alloys component and welding parameters on microstructures and properties of joint have been analyzed. The results indicate that the amorphous Ni-Si-B interlayer alloys have an excellent wettability and gap filling capability during transient liquid-phase bonding of 316L stainless steel and the microstructure of bonding joint are continuous without welding defects. The microstructures of welding seam consist of Ni(Fe) and a small amount of Cr₃C₂ phase, the base metal has no coarsening with identical lattice structures as the welding seam. The optimized bonding parameters are 50℃/s heat rate, bonding temperature 1150℃, holding time 10 min. The elements within joint diffuse sufficiently and the diffusion depth of Si in the base metal is about 35μm. The joint shows higher mechanical properties and its bending angle reaches to 135°.