ZrC复相陶瓷表面等离子喷涂ZrB2-SiC-ZrC陶瓷涂层的制备

Fabrication of ZrB2-SiC-ZrC Coating on ZrC Composite Ceramic by Plasma Spraying

为了提高ZrC陶瓷的高温性能,先采用Zr、Si和B4C原料粉末通过反应热压烧结制备ZrB2-SiC-ZrC喷涂粉末;再在喷砂处理后的ZrC复相陶瓷基体表面利用等离子喷涂技术制备ZrB2-SiC-ZrC涂层;对喷涂粉末的形貌及粒度、涂层的物相组成、表面和断面的显微组织及结合强度进行了分析和测试。结果表明:真空反应热压烧结法成功地制备出ZrB2-SiC-ZrC喷涂用材料,物相分析显示ZrB2、SiC和ZrC是主要的结晶相。涂层中的物相与喷涂前反应烧结试样的物相组成一致。不同喷涂条件下得到的ZrB2-SiC-ZrC涂层表面均呈凹凸不平的起伏形貌。涂层断面形貌显示,涂层与基体界面结合紧密,没有明显的开裂,涂层厚度均匀,表明采用等离子喷涂技术可以实现ZrC复相陶瓷上免粘结层的ZrB2-SiC-ZrC涂层的制备。

ZrB2-SiC-ZrC spraying powder was obtained by reaction hot pressing sintering using Zr,Si and B4C raw materials.ZrB2-SiC-ZrC coating was fabricated on the surface of grit-blasted ZrC ceramic by plasma spraying.The phase composition,surface and fracture section microstructures,and bonding strength of the coating were analyzed.Results showed that ZrB2-SiC-ZrC spraying materials were successfully prepared by vacuum reaction hot pressing sintering.Phase analysis showed that the dominant phases were ZrB2,SiC and ZrC.The phase composition of the coating was consistent with that of the sintered sample.The surfaces of the ZrB2-SiC-ZrC coatings under different spraying conditions appeared rugged.The fracture section of the coating showed that the interface between the coating and the substrate closely bonded,and no obvious cracking was observed.Moreover,the thickness of the coating was uniform.Consequently,the bond-free layer of ZrB2-SiC-ZrC could be prepared on ZrC composite ceramic by plasma spraying technology.