多孔碳纤维增强陶瓷基复合材料抗氧化烧蚀涂层的制备及性能研究

Preparation and Performance of Anti-Oxidation Ablative Coating of Porous Carbon Fiber Reinforced Ceramic Matrix Composite

为提高多孔碳纤维增强陶瓷基复合材料的耐烧蚀性设计了含玻璃的双层结构陶瓷涂层,内层为浆料烧结法制备的Zr B_2-Si C-玻璃涂层,外层为大气等离子喷涂技术制备的Zr B_2-Mo Si_2-玻璃涂层。利用XRD和SEM对涂层的相结构和微观形貌进行分析,采用氧-乙炔火焰对涂层进行烧蚀试验。结果表明,内涂层玻璃相含量为30%时封孔效果较好,在1300℃下烧结2 h可得到致密的内涂层。采用优化后的等离子喷涂工艺可以制备与内涂层结合性良好的外涂层。涂层表面温度在1500℃以下时具有良好的抗烧蚀性能。烧蚀氧化形成以Si O_2为填充相,Zr O_2、Zr Si O_4为支撑相的致密层,封填孔洞,有效保护了基体材料。

To improve the oxidation oblation resistance of porous carbon fiber reinforced ceramic matrix composite,double-layer structure ceramic coating was designed,and the Zr B_2-SiC-glass internal coating was prepared by a slurry sintering method,while the Zr B_2-Mo Si_2-glass coating was prepared by atmospheric plasma spraying in the outer layer.The phase structure and morphology of the coating were examined by XRD and SEM,and the coating was ablated by oxygen-acetylene flame,It is shown that the sealing effects is better when the glass content of the inner coating is 30%and dense inner coating can be obtained by sintering at 1300℃for 2 h.Outer coating having good adhesion with the inner coating was prepared by using optimized plasma spraying.The anti-erosion performance of the coating is good when surface temperature is below 1500℃.Ablation oxidation forms a dense layer with SiO_2 as the filling phase,ZrO_2,Zr SiO_4 as the supporting phase,and the pores are sealed which effectively protect the substrate material.