A dimensionless mathematical model for prediction of gas atomized powder particle size (D 50 )

Particle size control in gas atomization is essential for powder metallurgy processing, yet reliable prediction remains difficult due to the coupled influence of melt properties, gas dynamics and atomizer geometry. In this work, a dimensionless empirical model was developed to predict the median particle size (D₅₀) of gas-atomized powders. Twenty-six variables were reduced using Buckingham π analysis into three groups: melt parameter (Mp), gas parameter (Gp) and design parameter (Dp), which were correlated with dimensionless particle diameter. Copper powder was produced using a pilot-scale close-coupled atomizer under varying gas pressure, superheat temperature and nozzle configuration. A 3D map was plotted along with the 2D contour to locate optimum conditions for the desired powder particle size. An approximate generalised model has been established to resolve and identify the role of the influencing variables. The approach provides a practical tool for selecting atomization conditions to obtain the desired powder size.