PS-PVD 热障涂层显微结构对耐侵蚀性能的影响研究

采用等离子喷涂物理气相沉积 ( PS-PVD ) 技术开展了热障涂层梯度结构调控研究，通过调整喷涂送粉速率，在底部、中间和顶部沉积阶段制备了五种不同的热障涂层，对热障涂层的显微组织、粗糙度、孔隙率、耐熔盐腐蚀和耐粒子冲蚀性能进行表征，阐明了显微结构变化对热障涂层耐侵蚀性能的影响。研究表明：送粉速率的变化对PS-PVD热障涂层羽柱状结构的沉积有显著的影响，低送粉速率下，涂层底部结构比较致密，当送粉速率增大时，由于粉末颗粒在喷涂过程气化不充分，未熔粒子增加，羽柱状顶部结构趋向致密结构转变，涂层顶部孔隙率下降，表面粗糙度降低。送粉速率由底至顶梯度递增制备的涂层表现出较高的耐熔盐腐蚀性能和耐粒子冲蚀性能。

Study on the Influence of Microstructure of PS-PVD Thermal Barrier Coating on Corrosion Resistance

Plasma spraying physical vapor deposition ( PS-PVD ) technology was used to study the gradientstructure control of thermal barrier coatings. Five different thermal barrier coatings were prepared at thebottom, middle and top deposition stages by adjusting the powder delivery rate during the spraying process. Themicrostructure, roughness, porosity, resistance to molten salt corrosion and resistance to particle erosion of thermalbarrier coatings were characterized. The effect of microstructure change on corrosion resistance of thermal barriercoatings is discussed. The research shows that the change of powder delivery rate has a significant influence on thedeposition of PS-PVD thermal barrier coating plume structure. At low powder delivery rate, the bottom structureof the coating is relatively dense. When the powder delivery rate increases, the top structure of the plume tendsto be dense structure due to insufficient vaporization of powder particles during the spraying process, and theincrease of unmelted particles, the porosity of the top coating decreases, and the surface roughness decreases. The coating prepared by increasing the powder feeding rate from bottom to top shows higher corrosion resistance inmolten salt and particle erosion resistance.