Prediction of particle size for water atomised metal powders: Parameter study

This work aims to investigate how some significant atomising parameters influence the mass median particle size d₅₀ of water atomised metal powders. More specifically, these were water pressure, melt flowrate, water jet angle, liquid metal viscosity and surface tension. Existing models for the prediction of d₅₀ during water atomisation were reviewed. The selected models were fitted and compared with atomising experiments of liquid iron containing 0·5–4·4%C. Experimental results and model calculations were used in a parameter study to investigate how the different parameters influenced d₅₀. The effect on d₅₀ was large for the water pressure, medium for the viscosity and low for the melt flowrate and surface tension. Model calculations indicate that the jet angle has a large effect on d₅₀, which should be verified by additional studies. The model proposed by Bergquist (B. Bergquist: Powder Metall., 1999, 42, 331–343) showed the best agreement with the current experimental data.