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 10MPa and the welding temperature was 900℃

copper/304 stainless steel joint has the best shear strength of 98MPa. 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.