Low pressure atomization process of molten metal in a linear internal mixing atomizer

The dependence of atomization performance on the pressure difference between melt and atomization gas in a linear atomizer is investigated. The cross section area of the slit of the linear atomizer is 12 mm². The atomization pressure is in the range of 4.3 bar to 5.2 bar. The melt and atomization gas are first mixed in the mixing chamber and then injected through the slit of the atomizer. The particles are collected in a cooling chamber of one meter height. Results show that increase in the pressure difference between melt and atomization gas enhances the atomization performance. It is found that significant breakup of the bigger particles takes place when the pressure difference increases. Thus, controlling the pressure difference between melt and atomization gas can reduce the mean particle size and obtain a narrower size distribution. The yield rate of fine powder production increases accordingly. Our result compares favorably to the HPGA nozzle reported in the literature with the atomization pressure as high as 8 bar to 70 bar. Significant reduction in the production cost of metal powders has been achieved.