Production of gas-atomized aluminum alloy powders for metal additive manufacturing processes

Light alloys, such as aluminum or titanium alloys, have potential applications in the automotive and aerospace industries due to their low density and high specific strength. Gas-assisted atomization processes have been widely used in the industrial production of metal powders. The benefits of using gas-atomized metal powders in MAM (metal additive manufacturing) processes have been explored in recent studies. In this paper, a novel gas-assisted nozzle, which is designed with an internal melt pre-filming mechanism, is proposed to control the largest size of the gas-atomized aluminum powders. The atomization performance of this nozzle is investigated, and the powder size distribution is measured by a Coulter LS230 particle sizer. The results show that the particle size of the gas-atomized powders deceases as the atomization gas pressure increases. The gas-to-melt mass ratio is 0.24 under an atomization gas pressure of 5 bar. A mean particle size (D50) of 18.0 μm and maximum particle size (D90) of 35.9 μm have been achieved under a gas atomization pressure of 5 bar. The as-atomized AlSilOMg alloy powders produced in this work are able to meet the requirements of MAM processes.