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采用化学气相沉积(CVD)和浆料刷涂-烧结法制备了双层SiC/ZrB2-SiC-B4C涂层,对比研究了无涂层、单层SiC涂层和双层SiC/ZrB2-SiC-B4C涂层C/SiC复合材料在1500 ℃下的氧化和在4.2 MW/m2热流密度下的烧蚀性能.结果表明:制备态ZrB2-SiC-B4C涂层致密、完整,表面平均粗糙度约为1 μm,孔隙率约为4.2％.在1500 ℃氧化30h后,SiC/ZrB2-SiC-B4C涂层C/SiC复合材料的质量损失率约为10％,涂层表面氧化膜致密,无明显裂纹.高温烧蚀20 s后,SiC/ZrB2-SiC-B4C涂层的线烧蚀率和质量烧蚀率分别为1.0±0.3μm/s和1.1士0.2 mg/s,与单层SiC涂层相比分别降低了75.0％和50.0％,SiC/ZrB2-SiC-B4C涂层烧蚀后形成的ZrO2-SiO2氧化膜可以减缓火焰对复合材料的机械剥蚀.“,”Double-layered SiC/ZrB2-SiC-B4C coatings were fabricated by chemical vapor deposition(CVD)and slurry painting-sintering methods.The naked,single-SiC coated and SiC/ZrB2-SiC-B4C double-layered C/SiC composites were oxidized at 1500 ℃ and ablated under a heat flux of 4.2 MW/m2.The results indicate that the slurry-painted ZrB2-SiC-B4C coating is dense and intact,which has a surface roughness Ra of～l μm and the porosity of～4.2％.After oxidation at 1500 ℃ for 30 h,the mass loss ratio of SiC/ZrB2-SiC-B4C coated C/SiC composite is～10％.The oxidation scale on the coating surface is compact without obvious cracking.After ablating for 20 s,the linear and mass ablation rates of SiC/ZrB2-SiC-B4C coating are 1.0±0.3 μm/s and 1.1±0.2 mg/s,decreased by 75.0％and 50.0％relative to those of the SiC coating,respectively.The formed ZrO2-SiO2 scale provides a protection against the mechanical erosion from the flame.