Abstract A pressure-gas atomizer was developed, in which the melts were pressurized through melt nozzles with a small inner diameter, aiming for a small mass median diameter (MMD, d50,3) and high productivity of fine spherical powders. The maximum melt flow resistance in a melt nozzle, defined as the sum of the capillary resistance and viscous pressure drop, was analyzed by varying the inner diameter of the melt nozzle (D0). The calculation results indicate that the maximum melt flow resistance increases quickly with the decrease of D0, and varies in an order of 100–102 kPa for different metal melts when D0 reduces from 4.0 mm to 0.5 mm. Atomization runs with three kinds of aluminium (Al) alloys were accomplished using melt nozzles with different inner diameters in a pilot plant whereby an over-pressure in a range of ∆pl = 30–45 kPa can be maintained on the melts to enhance the melt flowing in the melt nozzle. The experimental results indicate that the atomization efficiency can be well improved by reducing the inner diameter of the melt nozzle, which resulted in a small MMD, narrow particle size distribution and high fine powder yield. For Al-I alloy powders, when the inner diameter of the melt nozzle reduces from D0 = 3 mm to D0 = 1 mm, the particle MMD reduces from d50,3 = 86.13 μm to d50,3 = 40.42 μm, and the powder yield

中文翻译：

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通过小内径熔体喷嘴在加压熔体的气体雾化过程中生产细球形粉末

摘要 研制了一种压力气体雾化器，通过小内径熔体喷嘴对熔体加压，旨在获得小质量中值直径（MMD，d50，3）和高产细球形粉末。熔体喷嘴中的最大熔体流动阻力定义为毛细管阻力和粘性压降的总和，通过改变熔体喷嘴的内径 (D0) 进行分析。计算结果表明，最大熔体流动阻力随着 D0 的减小而迅速增加，当 D0 从 4.0 mm 减小到 0.5 mm 时，不同金属熔体的最大熔体流动阻力变化范围为 100-102 kPa。在中试工厂中使用不同内径的熔体喷嘴完成了三种铝 (Al) 合金的雾化运行，由此可以在熔体上保持 Δpl = 30–45 kPa 范围内的过压以增强熔体在熔体喷嘴中流动。实验结果表明，通过减小熔体喷嘴内径可以很好地提高雾化效率，导致MMD小、粒度分布窄、细粉收率高。对于Al-I合金粉末，当熔体喷嘴内径从D0 = 3 mm减小到D0 = 1 mm时，颗粒MMD从d50,3 = 86.13 μm减小到d50,3 = 40.42 μm，粉末得率 实验结果表明，通过减小熔体喷嘴内径可以很好地提高雾化效率，导致MMD小、粒度分布窄、细粉收率高。对于Al-I合金粉末，当熔体喷嘴内径从D0 = 3 mm减小到D0 = 1 mm时，颗粒MMD从d50,3 = 86.13 μm减小到d50,3 = 40.42 μm，粉末得率 实验结果表明，通过减小熔体喷嘴内径可以很好地提高雾化效率，导致MMD小、粒度分布窄、细粉收率高。对于Al-I合金粉末，当熔体喷嘴内径从D0 = 3 mm减小到D0 = 1 mm时，颗粒MMD从d50,3 = 86.13 μm减小到d50,3 = 40.42 μm，粉末得率