Investigation on Porosity and Microhardness of 316L Stainless Steel Fabricated by Selective Laser Melting

This study investigates the porosity and microhardness of 316L stainless steel samples fabricated by selective laser melting (SLM). The porosity content was measured using the Archimedes method and the advanced X-ray computed tomography (XCT) scan. High densification level (>= 99%) with a low average porosity content (similar to 0.82%) were obtained from the Archimedes method. The highest porosity content in the XCT-scanned sample was similar to 0.61. However, the pores in the SLM samples for both cases (optical microscopy and XCT) were not uniformly distributed. The higher average microhardness values in the SLM samples compared to the wrought manufactured counterpart are attributed to the fine microstructures from the localised melting and rapid solidification rate of the SLM process.