超声速等离子喷涂氧化锆粒子时的加热熔化特性分析

Heating and Melting State of YSZ Particles in Supersonic Atmospheric Plasma Spraying

应用格林函数法求解超声速等离子喷涂(SAPS)过程中氧化钇稳定二氧化锆(YSZ)粒子的加热熔化时间问题,得到了一个解析解;对SAPS过程中粒子熔化时间和熔化界面推移情况进行了数值模拟,所得结果与实验结果相符.熔化过程的模拟结果显示:粒子的初始温度对熔化速率有一定的影响,喷涂前预热粒子可以加快它的熔化;减小粒子半径可以缩短粒子的熔化时间,提高粒子的扁平化程度.在SAPS过程中,通过过筛控制粒子半径有助于获得结构精细、致密的典型细密柱晶组织.

Yttria-stabilized zirconia（YSZ） based thermal barrier coatings（TBCs） are deposited by high efficiency supersonic atmospheric plasma spraying（SAPS） system.The phase change time in heating and melting of the particles in SAPS process is analytically gained with Green＇s function method,which gets relatively close to the experimental data.And the moving process of solid-liquid interface within a particle is clearly revealed.The heating and melting process is numerically simulated,and the effect of initial temperature on particle melting rate is observed.Pre-heating before spraying can accelerate melting.The melting time of the particle can be shortened and the flattening degree can be increased by reducing the particle radius.The particle radius can be controlled by sifting to fabricate a fine and compact structure with columnar grains.