论文部分内容阅读
针对超声速等离子喷涂过程中颗粒撞击基体前熔化状态未知的问题,利用数值计算方法分析了单个颗粒在超声速气流中的加热熔化过程,并对颗粒的破碎细化行为进行了探究。计算考虑颗粒内部相变后,得到不同时刻颗粒内部的温度分布更加合理,通过分析得到了颗粒熔化界面随加热时间的变化曲线,其在0.35ms时完全熔化,这与实验分析结果相符。熔融颗粒在进入到高温高速等离子体射流中粒径会迅速减小,统计得到100mm处小于5μm的颗粒所占比例最大,超过了50%,与实验收集粒子的粒度分布一致。
In order to solve the problem of unknown melted state of particles during the supersonic plasma spraying process, the heating and melting process of single particles in supersonic gas flow were analyzed by numerical method. The fragmentation behavior of the particles was also investigated. Calculating the internal phase transformation of the particles, it is more reasonable to obtain the temperature distribution inside the particles at different time points. The curve of the melting interface of the particles with the heating time is obtained, which completely melts at 0.35ms, which agrees with the experimental results. The particle size of molten particles decreases rapidly when they enter the high-temperature and high-speed plasma jet. The statistics shows that the proportion of particles smaller than 5μm at 100mm is the largest, exceeding 50%, which is consistent with the experimental particle size distribution.