From Melt Breakup To Powder Quality: Linking Atomization Dynamics To Particle Morphology And Size Distribution In Gas-atomized 316L Steel

Authors: Tatiana Fedina (Swerim AB, Sweden) Kevin Cheuk Hang Sze (Swerim AB, Sweden) Liviu Brabie (Swerim AB, Sweden) Stefan Heino (Swerim AB, Sweden) Lorenzo Fransecia (Swerim AB, Sweden) Christopher Hulme-Smith (KTH Royal Institute of Technology, Sweden) Abstract: Gas atomization is a key process for producing metal powders for powder metallurgy and additive manufacturing, where powder size distribution and morphology strongly affect processing and performance. This work examines melt breakup behavior during nitrogen gas atomization of 316L stainless steel and its influence on the resulting powder characteristics, with emphasis on the role of atomization pressure. High-speed imaging and image-based droplet tracking were used to study melt disintegration, ligament formation, and droplet evolution at different nitrogen pressures. The produced powders were characterized and correlated with in-flight observations. The results show that atomization pressure and temperature significantly affect breakup mechanisms and particle size distribution. Variations in pressure and temperature alter the stability, duration, and fragmentation pathways of the melt, leading to systematic changes in powder fineness. The study highlights the importance of understanding melt-gas interactions during atomization and demonstrates that process parameters can be adjusted to tailor powder properties. DOI: https://doi.org/10.59499/EP267157632