Microstructure Analysis of High-Density 316L Stainless Steel Manufactured by Selective Laser Melting Process

Selective laser melting (SLM) is used to fabricate nearly fully dense 316L stainless steel (SS) samples in this study. A variety of advanced characterization techniques were conducted to identify dominant phases, important crystallographic features, microstructural features, and elemental composition. Porosity of the sample was found to be 0.02% which is the lowest porosity content reported for SLM-processed 316L SS. Microstructural analysis exhibits some columnar grains with epitaxial growth representing complete adhesion between the layers. Existence of some fine cellular grains inside the melt pools is an indication of rapid solidification during the printing process. The strength of this study lies in the addition of new crystallographic information such as lattice parameters of SLM-processed 316L. Finally, using information obtained from the literature, it was possible to better understand the effect of chosen process parameters to achieve nearly fully dense material in the present study.