SPS温度对铜/镍粉/304不锈钢接头组织与剪切强度的影响

Influence of SPS Temperature on Microstructure and Shear Strength of Copper/Nickel Powder/304 Stainless Steel Joints

采用脉冲放电等离子烧结(SPS)制备了添加镍粉中间层的铜/304不锈钢接头,研究了焊接温度对接头组织及力学性能的影响。结果表明,以镍粉为中间层,可以实现铜与304不锈钢的扩散焊接。铜/镍界面处铜、镍互扩散形成铜/镍界面扩散层,镍/304不锈钢界面处镍、铁互扩散形成镍/铁界面扩散层,铜/镍扩散层厚度大于镍/铁扩散层厚度。在焊接压力为10 MPa、焊接温度为900℃时,铜/304不锈钢接头剪切强度最佳,为98 MPa。铜/304不锈钢接头断口形貌呈韧窝状,断裂均在镍中间层处,接头连接强度受制于镍中间层本身的强度。

Copper/304 stainless steel joints with nickel powder were prepared by spark plasma sintering（SPS）. The influence of welding temperature on the microstructure and mechanical properties of the joint was studied. Copper and 304 stainless steel can be welded by using nickel powder as inter-layer. Cu/Ni diffusion layer and Ni/SS304 diffusion layer formed at the joint interface because of the elemental inter-diffusion. The results showed that the diffusion of copper in nickel is greater than that in stainless steel, and the thickness of Cu/Ni diffusion layer is larger than that of Ni/SS304 diffusion layer. When the welding pressure was 10 MPa and the welding temperature was 900℃, copper/304 stainless steel joint has the best shear strength of 98 MPa. Shear fracture morphology shows that copper/304 stainless steel joint has plasticity and its fracture morphology was dimple, and the copper/stainless steel joint breaks at the middle of the nickel inter-layer due to its low adhesive strength. The joint strength was limited by the strength of the nickel inter-layer.