Additive Manufacturing of Cu on 316L Stainless Steel via Inconel 718 Intermediate Layers

Joining of dissimilar materials is becoming increasingly prevalent to combine differing material properties to enhance product design flexibility and performance. In this study, pure copper was built on 316L stainless steel (SS316L) by laser-based additive manufacturing technology in which copper was deposited layer-by-layer on SS316L with Inconel 718 intermediate layers. The goal is to fabricate multi-metallic structures with improved thermal conductivity. The direct joining of Cu on SS316L would result in porosities at the interface and the consequent poor mechanical properties, which could be addressed by Inconel 718 intermediate layers. The microstructure, chemical composition, tensile properties, and micro-hardness were characterized in the dissimilar materials using scanning electron microscopy, energy dispersive spectroscopy, tensile test with digital image correlation technique, and hardness tester. Results confirm excellent bonding when Inconel 718 intermediate layers are introduced.