Investigations into the interfacial characteristics of Inconel 718/stainless steel 316L fabricated by multi-material Laser Powder Bed Fusion.

The numerous advantages of Additive manufacturing (AM) are being utilized to print multi-material components for different applications. Although the AM method of laser powder bed fusion (LPBF) can print more complex and dimensionally accurate parts than the directed energy deposition (DED) method, printing multi-material components is challenging for LPBF. This study demonstrates an attempt at bimetallic 3D printing of stainless steel 316L and Inconel 718 by multi-material laser powder bed fusion and its characterization. A continuous wave (CW) fiber laser was used for the LPBF process and laser parameters for the bimetallic components were optimized. Microstructural studies were carried out with optical microscopy and scanning electron microscope (SEM) to investigate the interfacial characteristics for different numbers of interlayers. The thickness of the interfacial region was around 50-100 μm. Vickers microhardness (HV) and nanoindentation were performed at various locations around the fusion zone resulting in an average micro and nano hardness of 303 HV and 4.622 GPa respectively.