Suspension plasma spraying (SPS) technology allows the production of advanced coatings via deposition of micron and submicron particles, however its effective implementation requires a deep understanding of “droplet – plasma” interaction. Droplets of suspension in a jet drastically change their size due to fragmentation and evaporation of the liquid carrier, a change in the structure of particles occurs, and several processes of mass and heat transfer take place. This paper analyzes the time scales of the droplet breakup, convective (Hill vortex) and diffusion mass transfer of solid phase in a suspension, heating and evaporation of the material, vapor transport due to diffusion and filtration mechanisms. Basing on these analyses, a phenomenological model of the evolution of suspension droplets in the SPS process is proposed. The model includes the stages of a breakup, diffusion drying and the formation of a dry crust, the filtration exit of vapors, and the final heating and melting of the material. A 1-D simulation of the behavior of droplets of a ZrO₂ suspension in a uniform air plasma flow was carried out, the influence of the velocity (500–2500 m/s) and temperature (3000–5000 K) of the plasma, the concentration of the suspension (1–60% wt) on the characteristics of the sprayed particles was studied. It was found that after formation of surface crust the vapor pressure inside the particles can reach 1 MPa, and filtration mass transfer of vapor must be considered when analyzing the problem. Equations have been obtained for estimating the size and temperature of particles and duration of each stage of droplet evolution.

悬浮等离子喷涂（SPS）技术允许通过沉积微米和亚微米颗粒来生产先进的涂层，但是其有效实施需要对“液滴-等离子体”相互作用的深刻理解。由于液体载体的碎裂和蒸发，喷射器中的悬浮液液滴会极大地改变其大小，发生颗粒结构的变化，并且发生质量和热传递的若干过程。本文分析了液滴分裂，对流（希尔涡）和固相在悬浮液中的扩散传质，材料的加热和蒸发，由于扩散和过滤机制而产生的蒸汽传输的时间尺度。在此基础上，提出了SPS过程中悬浮液滴演化的现象学模型。该模型包括分解，扩散干燥和形成硬皮的阶段，蒸气的过滤出口以及物料的最终加热和熔化的阶段。ZrO液滴行为的一维模拟在均匀的空气等离子体流中进行了_2次悬浮，其中等离子体的速度（500–2500 m / s）和温度（3000–5000 K），悬浮液的浓度（1–60％wt）对研究了喷雾颗粒的特性。发现在形成表面结壳后，颗粒内部的蒸气压可以达到1MPa，并且在分析问题时必须考虑蒸气的过滤传质。已经获得了用于估计颗粒的大小和温度以及液滴发展的每个阶段的持续时间的方程式。