液相等离子喷涂纳米ZrO2热障涂层的显微结构及抗热震性能研究

采用液相等离子喷涂技术制备了纳米氧化锆热障涂层。用透射电镜、扫描电镜和X射线衍射研究了涂层的晶粒特性、显微结构和晶体结构,同时研究了纳米氧化锆热障涂层的热震性能。结果表明:液相等离子喷涂制备的涂层晶粒约30nm;涂层具备均匀的孔隙结构;涂层热震前后的主相为稳定的四方相晶体结构;涂层的特殊孔隙结构有利于缓解热震循环过程中产生的应力、阻止裂纹的形成和扩散,从而提高了涂层的抗热震性能。

Microstructure and Thermal Shock Resistance of Solution Precursor Plasma Spray Nanostructured ZrO2 Thermal Barrier Coatings

The nanostructured ZrO2 thermal barrier coatings(TBCs) are deposited by Solution Precursor Plasma Spray(SPPS).The analysis methods,such as TEM,SEM,and XRD are used to characterize the coatings in the aspects of grain,microstructure and phase compositions..The thermal shock resistance of the nanostructured coatings was measured by forced-air.Experimental results show that grain size of the SPPS TBCs is about 30nm with uniform pore structure and desired tetragonal phase ZrO2.The special pore structure were benefit to relieve the stress of the coatings,diminish the driving force for the initiation and propagation of cracks,so the thermal shock resistance of the coatings was improved.