Water atomisation of metal powders: effect of water spray configuration

ABSTRACT

We consider the effect of water spray configuration on the fineness and uniformity of a metal powder produced by water atomization of a melt stream. The effects of water spray travel distance, nozzle design, water pressure, melt superheat, and apex angle on the particle size distribution of a metal powder is studied via a laboratory-scale water atomizer; the main focus is on the first two, which are usually fixed parameters of the atomizer. Correlations are proposed relating the mass median size and standard deviation of the powder to the parameters cited. Similar correlations for water pressure, melt superheat, and apex angle have been reported elsewhere; we present data on these effects to confirm the validity of our results, especially as Bi-42%Sn powder has not been studied before. What is new are results on the effect of water spray travel distance and nozzle design on the mass median size and standard deviation of powder.