Chemical analysis, structure and mechanical properties of discrete and compositionally graded SS316-IN625 dual materials

Discrete and compositionally graded dual materials based on SS316 and IN625 alloys were made using LENS process by layer wise deposition, controlling feed rates of individual alloy powders. The two-alloy interface regions were characterized with respect to microstructure, elemental distribution, micro-hardness, and tensile properties of the deposits. For discrete as well as graded deposits, change in composition near the interface is gradual. This observation is explained on the basis of dilution by the substrate. Irrespective of whether the variation in powder feed rate is changed gradually or discretely, the yield strength of the materials is always comparable to that of the lower strength material of the two, viz., SS316 and failure occurred within SS316 indicating good bonding in the two alloy interface region.