Research progress on mechanisms and technologies of gas atomization for metal powder preparation

【Objective】 With the rapid development of fields such as aerospace, medical, and new energy vehicles, there arose a growing demand for the efficient and cost-effective preparation of high-performance metal powders. Therefore, this paper aimed to summarize the developmental history of numerical simulation and atomization mechanisms, reviewed advancements in gas atomization equipment, and systematically examined the effects of process parameters to promote the further development of gas atomization technology.
【Method】 A comprehensive review of recent research on gas atomization technology was conducted. The study evaluated the application of numerical simulation models, specifically examining the Volume of Fluid (VOF) model for primary atomization and the Discrete Phase Model (DPM) for secondary atomization, to elucidate the complex, high-speed fragmentation processes. Additionally, it investigated the structural designs of atomizers, focusing on the differences between free-fall and close-coupled atomizers, as well as nozzle configurations. Finally, the paper analyzed the influence of critical process parameters, including atomization gas pressure, gas temperature, melt superheat, melt stream diameter, and the gas-to-liquid mass ratio, on the final powder characteristics.
【Result】 Numerical simulations prove highly effective in visualizing unobservable phenomena, demonstrating how high-speed gas transforms metal melt into fine droplets that subsequently undergo spheroidization and solidification. Research on atomizer structures indicates that optimizing elements like the gas injection angle, delivery tube length, and nozzle aspect ratio significantly influences gas velocity and prevents nozzle blockage, thereby improving fine powder yield. Furthermore, process parameter adjustments play a pivotal role, increasing gas pressure and temperature generally enhances gas kinetic energy, leading to a reduction in powder particle size. Properly adjusting the melt superheat helps decrease surface tension and viscosity, which alters the droplet fragmentation mode and improves powder sphericity while reducing the formation of satellite particles.
【Conclusion】 The review concluded that optimizing atomizer structures and process parameters directly dictated powder quality. It also suggested that future research needed to transition from single-factor analyses to investigating the interactive effects of multiple parameters. Furthermore, future developments required the creation of continuous numerical models that seamlessly coupled primary and secondary atomization stages, as well as the utilization of big data and imaging technologies to validate simulation results.