等离子体熔化离心雾化喷涂粒子的特性

研制了一种基于离心雾化原理的内孔热喷涂设备，简要介绍了该设备的工作原理和粒子的雾化过程。对试验收集的雾化粒子进行了观察与统计分析，用扫描电镜观察了雾化粒子的表面形貌，并统计分析了消耗电极在不同转速下的粒子粒度及其分布。结果表明，雾化粒子的球形度较好，粒度较均匀。还研究了消耗电极转速和直径的变化对粒子粒度以及粒度变化率的影响。分析表明：提高消耗电极的转速和直径会使粒子的粒度减小；但是，当电极转速和直径增大到一定程度后，继续增大这2个参数对粒子直径变化的影响将大大减小，说明存在一个最佳的消耗电极转速和直径范围，在此范围内设备稳定性和喷涂粒子直径都可以达到最佳。

Characteristics of particle formed by plasma arc melting centrifugal atomizing spray process

A thermal spray equipment for bore surface coating based on centrifugal atomization was developed, the atomization principle and particles formation process of the equipment were introduced. The particles formed by the equipment were collected for observation and statistic analysis, particle surface morphology was observed by using SEM, variations of particles size and their distribution in different rotational velocity of consumable electrode were studied, the results show that the particles produced possess good sphericity, and its size decrease with increasing rotating speed. The influences of the rotation speed and diameter of the consumable electrode on particle size and the rate of change of particle size were investigated, the results show that while particles size decrease with increasing rotating speed, the effects will be substantially reduced when the rotation speed and diameter of the consumable electrode attain certain value, which means that there exists a range of rotation speed and diameter of the consumable electrode that can lead to an optimum spray operation concerning particle size and equipment stability.