锆酸镧金属复合热障涂层显微结构及力学性能研究

Study on Microstructure and Mechanical Property of La_2Zr_2O_7 and NiCoCrAlY Thermal Barrier Coatings

采用微弧等离子法在1Cr18Ni9钢基体上制备了La2Zr2O7、NiCoCrAlY复合热障涂层。采用扫描电镜、X射线衍射仪、拉伸试验仪等仪器研究了涂层的显微结构及力学性能。结果表明:涂层表面较为平整,其中镶嵌有未完全熔化的La2Zr2O7颗粒;涂层为典型的层状结构;涂层较为致密且分布有均匀的空隙、微裂纹及未完全熔化的颗粒等缺陷;La2Zr2O7、NiCoCrAlY在喷涂过程中未发生化学反应,保留了各自的相结构;涂层中的La2Zr2O7为烧绿石结构;涂层结合强度为31.9MPa。

The La2Zr2O7 and NiCoCrAlY thermal barrier coatings on 1Cr18Ni9 substrate were prepared by multi micro-arc plasma method. The microstructure and mechanical properties were studied by means of SEM,XRD and electron tensile tester. The results show that,the coating surface which scattered some semi-melted La2Zr2O7 particles is smooth. The coatings have typical laminar structure,some pores,microcracks,and semi-melted particles. None chemistry reaction occurs between La2Zr2O7 and NiCoCrAlY. La2Zr2O7 in the coatings is still pyrochlore phase. The adherent strength of the coatings is 31.9 MPa.