EFFECT OF NOZZLE DESIGN ON ALUMINUM POWDER PRODUCED BY LABORATORY SCALE ATOMIZER

Abstract

Poor nozzle design affects the quantity of the aluminium powder produced from a laboratory scale atomizer. This is as a result of the non-optimization of the atomizing fluid required to cause effective disintegration of the melt stream into particulate powder. In order to maintain thin stable melt film droplet for enhancing the particle size distribution, this study investigates the influence of variation in the angle of attack of pressurised air medium on a designed  laboratory-scale air atomizer for producing aluminium powders. Particle mean diameter ranging from 3 - 200μm was obtained for 40o angle of attack, 14 mm nozzle diameter, and 12bar operating pressure, while particle mean diameter ranging from 75-250μm was obtained for 45oangle of attack at the same operating conditions. The result shows that 40o angle of attack produced optimum yield Aluminium powder. Also, the disintegration mechanism, solidification behaviour, and powder properties were in agreement with previous research works on air atomization process. The implication of the findings from this study confirms the attainment of the appropriate angle of attack (40o) of the atomizing medium in producing aluminium powders having narrow size distribution at higher production efficiency and low costs.