Effect of Atomization on the Surface-Oxide Composition of 316L Powders for AM

Dmitri Riabov, Eduard Hryha, Sven Bengtsson

Chalmers University of Technology, Höganäs AB

In order to increase the utilization of laser powder bed fusion, decreasing the cost and improving powder recyclability is necessary. The majority of work on powder recyclability has focused on how powders degrade during L-PBF processing and its impact on the component performance. Few studies has examined the initial state of powder surface oxides, and no recent studies have examined their variation as a function of the atomizing media. This work summarizes a detailed surface characterization of three 316L powders, that were produced using water atomization and gas atomization with either argon or nitrogen. XPS and detailed SEM analysis were combined to characterize the surface oxide compositions, speciation and thickness. The findings indicate that the oxidation of elements with high oxygen affinity as e.g. Cr, Si, etc., varies significantly with the used atomization media. A brief discussion regarding the importance of the initial powder state on powder recyclability is given.