Sinterability of SS316, SiC, and TiN multi-material additive manufacturing via selective laser sintering

Additive manufacturing (AM) or 3D-printing (3DP) has revolutionized the manufacturing world through its ability to rapid-printing complex designs, process a variety of materials, and economically viable. This one-step manufacturing captured countless aerospace, automotive, biomedical, construction, electronics, and energy businesses. With recent developments, AM is not limited to single-material printing. Multi-material additive manufacturing (MMAM) provides a freeway of fabricating components with tailored physical properties to produce never before seen parts and structures. MMAM is in its infancy causing inconsistency in build quality, material compatibility, lack of fusion, porosity, cracks, ball formation, wettability, and issues with surface roughness were recurrent. The present study describes the fabrication of a multi-material laminate structure of SS316, SS316 with SiC 15% by weight, and TiN using laser powder-bed fusion. FESEM images confirm the agglomeration of sintered powder particles, the paving phenomenon of the next deposited layers, the increase of ball formation with increasing scanning speed due to instability associated with capillary action and splashing of molten metal, and the formation of columnar dendritic microstructure due to directional solidification caused by SiC and TiN powder particles. The microhardness values of the SS316 layer was increasing along the build direction and there was no significant change in the microhardness of SS316 with SiC (15% by weight) and TiN layers due to large temperature differences among the sintered powder particles. The COF values of sintered sample range from 0.137 to 0.128. X-ray diffraction (XRD) analysis confirmed the formation of & alpha;-iron (pearlite), & gamma;-iron (austenite), Fe1.76Ni0.16, C1Cr2Fe14, andC0.8Cr0.579Mo0.42 phases as a result of series of a chemical reaction between different elements of sintered multi-materials in the argon atmosphere.