Investigation of the influence of the delivery tube position on liquid aluminum atomization

Gas atomization technology is one of the most essential technologies for preparing metal powders. With this process, the liquid metal flowing from the melt delivery tube is atomized through a high-velocity gas sprayed from a nozzle with an angled. In this work, the variation of the position of the melt delivery tube on the pressure at the tip of the delivery tube was investigated, and the effect of mass median diameter, particle size distribution, and yield was experimentally studied and analyzed. A melt atomization unit is used to produce aluminum powders. Three configurations were selected for this study, that is, sag, critical, and prominence positions concerning the outlet hole of the nozzle. Three pressure states (pressurization, atmospheric, and aspiration) were established by varying the relative distance between the delivery tube and the gas outlet orifice-based surface. Experimental studies showed that the yield gradually increased at critical and prominence positions at low pressure and decreased at sag positions, providing significantly lower yields. At higher pressure, yields at critical and prominence positions gradually reduced, with prominence positions at 3 MPa producing powders with smaller average particle sizes and higher yields. Therefore the 3 MPa in the prominence position is best suited for metal atomization using a free-fall configuration.