Combining dissimilar materials in a single component is an effective solution to integrate diverse material properties into a single part. Copper-stainless steel hybrid components are attracting more and more attention since the high thermal conductivity of copper can greatly enhance the thermal performance of stainless steel, which benefits its applications in many industries. However, direct joining of copper and stainless steel such as SS316 L is challenging since they preserve significant dissimilarities in physical, chemical, and thermo-mechanical properties. This paper aims to fabricate well-bonded copper-SS316 L hybrid parts using a laser-aided directed energy deposition (DED) process. A nickel-based alloy Deloro 22 (D22) is introduced between copper and SS316 L to address the detrimental issues in copper-SS316 L direct joints. Using this technique, defect-free interfaces are achieved at both the D22-SS316 L and copper-D22 transition zones. Tensile testing of Cu-D22-SS316 L and D22-SS316 L hybrid parts shows the fracture occurs at pure copper and SS316 L region, respectively, indicating an excellent bonding at the interfaces. Ascending in the building direction, a transition of grain structure is observed. A significant diffusion zone is obtained at both the D22-SS316 L and the Cu-D22 interfaces. The large diffusion distance results in a smooth variation in microhardness over the dissimilar materials. The microhardness increases from SS316 L to D22 with the highest value of 240 HV and then decreases from D22 to Cu with the lowest value of 63 ± 4 HV. Testing of thermophysical properties of the Cu-D22-SS316 L system indicates there is a ∼300 % increase in thermal diffusivity and a ∼200 % increase in thermal conductivity when compared to pure SS316 L. The significant increase in thermal diffusivity and conductivity validates the enhanced thermal performance of SS316 L when it is joined with pure copper.

将异种材料组合到单个组件中是将多种材料特性集成到单个零件中的有效解决方案。铜-不锈钢混合组件越来越受到关注，因为铜的高导热性可以极大地提高不锈钢的热性能，这有利于其在许多行业中的应用。但是，铜和不锈钢（例如SS316 L）的直接连接具有挑战性，因为它们保留了物理，化学和热机械特性方面的显着差异。本文旨在使用激光辅助定向能量沉积（DED）工艺制造粘合良好的铜-SS316 L混合零件。在铜和SS316 L之间引入了镍基合金Deloro 22（D22），以解决铜-SS316 L直接接头中的有害问题。使用这种技术，可以在D22-SS316 L和铜-D22过渡区实现无缺陷的界面。Cu-D22-SS316 L和D22-SS316 L混合零件的拉伸测试表明，断裂分别发生在纯铜和SS316 L区域，表明在界面处具有出色的结合力。沿建造方向上升，观察到晶粒结构的转变。在D22-SS316 L和Cu-D22界面处都获得了明显的扩散区。大的扩散距离导致不同材料上的显微硬度平滑变化。显微硬度从SS316 L增大到D22，最高值为240 HV，然后从D22减小到Cu，最低值为63±4 HV。