Characterization and Cold Spray Performance of Ultrasonically Atomized 316 Stainless Steel Powders

Ultrasonic atomization is an innovative and highly promising technology for producing spherical, satellite-free metal powders for additive manufacturing. Beyond the high quality of the powders produced, this process enables the production of small batches, making it ideal for early-stage development applications in cold spray, particularly those requiring specialized powder compositions. In this study, 316 stainless steel powders produced by ultrasonic atomization were characterized in terms of size, shape, hardness and microstructure. Their cold sprayability was assessed by calculating deposition efficiency and examining coating microstructures. For comparison, trials were also conducted using commercially available gas-atomized powders. The ultrasonic atomization process yielded powders with high sphericity and low defect levels, ensuring easy powder feeding. Comparable deposition efficiencies (around 50%) and coating microstructures were achieved for both ultrasonic and gas-atomized powders of similar size. However, the ultrasonic atomized powders exhibited unique microstructural and surface characteristics that necessitate further investigation to fully understand their impact on powder deformability and bonding.