Oxide Dispersion Strengthened (ODS) SS316L Prepared by Laser Powder Bed Fusion (L-PBF): Analysis of Microstructure and Hardness Properties

In this paper, dense oxide dispersion-strengthened (ODS) SS316L with 0.5 wt.% Y2O3 was fabricated using nano-Y2O3-embedded spherical SS316L powder via laser powder bed fusion (LPBF). The molten pool, oxide dispersion, cellular structure, and microhardness of the as-printed ODS SS316L were investigated through optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-Ray Spectroscopy (EDX), and Vickers hardness testing, respectively. The results reveal a uniform dispersion of Y-rich nanoparticles in as-printed ODS SS316L, contributing to the development of a fine-grain structure in the as-printed ODS SS316L. A wide and shallow molten pool was observed in as-printed ODS SS316L, and enhanced microhardness was observed in ODS SS316L compared to pristine SS316L. The effects of Y2O3 on microstructure evolution and reinforcing mechanisms of microhardness are discussed.