Effect of Ni interlayer on partial transient liquid phase bonding of Zr–Sn–Nb alloy and 304 stainless steel

• Zr–Sn–Nb alloy and 304 stainless steel are successfully joined by means of PTLPB.
• IMCs are compact and cracks are formed in reaction layer of the joint without Ni.
• Many α-Zr phases dispersedly exist in reaction layer of the joint with Ni interlayer.
• The bonding strength of the joint increases by using Ni interlayer.

Zr–Sn–Nb alloy and 304 stainless steel were joined by means of partial transient liquid phase bonding. The effects of Ni interlayer on the microstructure and properties of the joints were investigated. The reaction layers are formed in both joints and which are mainly composed of σ-FeCr layer, Zr(Cr, Fe)2 + α-Zr layer and α-Zr + Zr2(Ni, Fe) layer. The intermetallic compounds are compact relatively and cracks are formed in the reaction layer of the direct bonded joint. In the joint with Ni interlayer, many α-Zr phases dispersedly exist in the reaction layer and the thickness of the reaction layer is distinctly larger than that without Ni interlayer. As a result of lower residual stresses and wider crack-free reaction layer, the bonding strength of the joint increases by using Ni interlayer.