Fabrication of SS316L-IN625 functionally graded materials by powder-fed directed energy deposition

摘要

In this work, functionally graded materials of Stainless Steel 316L and Inconel 625 were fabricated using Directed Energy Deposition. Intermediate layers were built in between of SS316L and IN625. Pure SS316L and IN625 samples were also prepared. The results show microstructure varied sharply at the interface on pure SS316L and IN625 while changed gradually on gradient samples. Quantitative analysis reveals the consistence of designed and tested material composition at the gradient layers. Tensile testing shows the yield strength of graded samples is similar to that of pure IN625 while the ultimate tensile strength is approaching to that of pure SS316L due to the fracture at SS316L side. Microhardness measurements reveal the gradual change of hardness values over the gradient zone.