Effect of feed metal flow rate on low-cost plasma atomizer for fabricating 316L stainless steel powder

The low-cost plasma atomizer in the present study successfully synthesized stainless steel spherical powder using an energy source of less than 3 kVA. Repeated testing was conducted to examine the resulting spherical powder, among other observations, using a digital microscope (Dino-Lite AM4115), scanning electron microscopy (SEM-FEI-Inspect F50), and energy dispersive spectroscopy (EDS). To ensure the purity of the resulting 316L stainless steel spherical powder, EDS was used for qualitative and quantitative elemental analysis. The results showed that the 316L stainless steel spherical powder particles varied in size from 26 μm to 180 μm with average particle diameters of approximately 82.6 μm, making them ideal for biomedical applications. The results of the feed metal flow rate on the powder weight percentages for particle sizes <50 μm for 2 mm³/s feed metal flow, 3 mm³/s feed metal flow, and 4 mm³/s feed metal flow were 26.04%, 28.04%, and 13.09%, respectively. It is possible that this could occur because greater metal flow rates require greater plasma energy to form liquid metal droplets, so that a lower metal flow rate at the same energy consumption makes it possible to produce more metal powder in smaller particles.