Influence of surface oxide characteristics and speciation on corrosion, electrochemical properties and metal release of atomized 316L stainless steel powders
Surface oxide characteristics of powder particles are important to consider for any toxicological risk assessment based on in-vitro or in-vivo tests. This study focuses on a multi-analytical approach (X-ray photoelectron spectroscopy, Auger electron spectroscopy, scanning- and transmission electron microscopy, and different electrochemical techniques) for in-depth characterization of surface oxides of inert-gas-atomized (GA) AISI 316L stainless steel powder, compared with massive sheet and a water-atomized (WA) 316L powder. Implications of differences in surface oxide phases and their surface distribution on corrosion, electrochemical properties and metal release are systematically discussed. Cr was enriched in an inner surface layer for both GA powders, with Mn and S enriched in the outermost surface oxide. The surface oxide was 2-5 nm thick for both GA powder size fractions, amorphous for the GA powder size
