GAS ATOMIZATION OF FINE ALUMINUM ALLOY POWDER Mat

摘要

The 6061 aluminum alloy ingots were gas atomized using a small-scale close-coupled atomization system. The process parameters such as gas pressure, melt rate and top pressure were varied accordingly in order to obtain the mean particle diameter (d_(50)) of the raw powder of about 20μm. In general, it was observed that increasing atomized gas pressure increased the amount of fine powder. At constant atomizing gas pressure and melt rate, increasing top pressure decreased slightly the amount of fine powder. The powder mean particle size (d_(50)) of 21.6μm and 14.5μm measured by laser particle size analyzer was obtained in the first and second collector of the atomizer respectively. This powder was produced at the gas pressure of 60 bar, superheat temperature of 1200℃ and gas to melt ratio of 5.46 m~3/kg. For this type of closed-coupled atomization system, it is concluded that it is not possible to obtain100% powder with mean particle diameter (d_(50)) of less than 20μm by varying the above process parameters.