Preparation of Monosized Spherical Particles by Pulsated Orifice Injection Method.

发展了一种新的能够制备单一尺寸金属颗粒的方法，称为脉动孔板注入法(POIM)，该方法是利用压电致动器给出的传压膜片的夹持作用，将熔融金属从小孔板上喷射出来。每个脉冲压力由隔膜的周期性位移引起，产生一个大小几乎等于孔口直径的液滴。成功地制备了铅锡合金金属粉末，其颗粒形状为球形，表面光滑，平均粒径的标准偏差为2%，小于传统的等离子体旋转电极法制备的颗粒。讨论了工艺参数对颗粒形成的影响，以及液滴喷射动力学。

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.