Preparation of Monosized Spherical Particles by Pulsated Orifice Injection Method.

本文提出了一种制备单尺寸金属颗粒的新方法——脉动孔注射法（POIM），该方法通过压电致动器对传压膜片的剪切作用，将熔融金属从一个小孔中注射出来。由隔膜周期性位移引起的每个脉冲压力产生的液滴的大小几乎等于孔直径。成功制备了Pb-Sn合金金属粉末，颗粒形状为球形，表面光滑，平均粒径标准差为2%，小于传统等离子体旋转电极工艺制备的颗粒。讨论了工艺参数对颗粒形成和液滴注入动力学的影响。

A novel method being capable of preparing monosized metal particles, termed pulsated orifice injection method (POIM), has been developed, in which molten metal was injected from a small orifice by a clipping action of a pressure transmitting diaphragm given by a piezoelectric actuator. Each pulse pressure, induced by periodic displacement of the diaphragm, produced a liquid droplet having a size almost equal to the orifice diameter. Preparation of metal powders of Pb-Sn alloy was demonstrated in a successful manner, where the shape of the particles is spherical with smooth surface and the standard deviation of the mean particle diameter is 2%, which is less than that for particles prepared by conventional plasma rotating electrode process. The effect of process parameters on the particle formation, as well as the kinetics of liquid droplet injection, was discussed.