浆料-烧结法制备ZrB2-SiC-B4C涂层及性能研究

Preparation and Property of ZrB2-SiC-B4C Coatings by Slurry Paintingsintering Method

通过浆料刷涂-烧结法在Cf/SiC复合材料表面制备了ZrB2-SiC-B4C超高温陶瓷涂层,研究了浆料中粉末填料、稀释剂的质量分数及高温烧结温度对涂层形貌、成分和相组成的影响。结果表明:当粉末填料与树脂质量比为1∶1、稀释剂与树脂质量比为1∶2、高温烧结温度为1500℃时,在Cf/SiC表面可形成致密、结合力强的ZrB2-SiC-B4C涂层。涂层内部相组织均匀,Ra<1μm,孔隙率约为4.2%,平均拉伸剪切强度约为5.4 MPa。1500℃等温氧化30 h后,有涂层Cf/SiC复合材料的失重率约为10.7%,涂层表面形成了完整的含有ZrO2-SiO2的复合氧化膜,为基体提供了有效的氧化防护。这说明Cf/SiC复合材料表面涂覆ZrB2-SiC-B4C涂层有望满足高温燃流环境的使用要求。

ZrB2-SiC-B4C ultra-high temperature ceramic coatings were prepared on Cf/SiC substrate surface by slurry painting-sintering method.The effects of the mass fraction of powder filler,diluent in slurry and the sintering temperature on the microstructure,composition and phases of ZrB2-SiC-B4C coating were studied.The results indicate that a dense and well-bonded ZrB2-SiC-B4C coating can be obtained on Cf/SiC substrate surface when the mass ratio of powder to resin is 1∶1,the mass ratio of diluent to resin is 1∶2,and the sintering temperature is 1500℃.This coating has uniform phases,low surface roughness of Ra<1μm,low porosity of around 4.2%,and high average tensile shear strength of about 5.4 MPa.After isothermal oxidation at 1500℃ for 30 h,the weight loss of ZrB2-SiC-B4C coated Cf/SiC composite is around 10.7%.An intact ZrO2-SiO2 film is formed during the oxidation,which provides the effective anti-oxidation protection.Thus,the ZrB2-SiC-B4C coated Cf/SiC composite can be a candidate material for applications in the high temperature combustion flow environment.