Effect of Atomizer Disc Geometry on Zinc Metal Powder Production by Centrifugal Atomization

摘要

The purpose of this paper is to demonstrate the influence of atomizer disc shape and size on the characteristics of zinc metal powder produced by centrifugal atomization.Two types of atomizer disc were employed,the flat disc and the cup-shaped disc with diameters of 30 and 50 mm for each type.The atomization was carried out in ambient air atmosphere,at pouring melt temperature of 550°C.The molten zinc was fed by gravity through a 1.0 mm nozzle with melt flow rate of approximately 50 kg/hr onto the atomizer disc spinning with a speed of 30,000 rpm.It was found that,the median particle size of zinc metal powder was decreased with increasing atomizer disc size.The cup-shaped disc gave better powder production with smaller particle median size and higher production yield.SEM images revealed that most zinc metal particles were irregular,ligament and elongated flakes.The oxygen in air might inhibit the spheroidization of melt droplet during solidification.