C/C-SiC-ZrB_2多元炭陶复合材料烧蚀性能

Ablation behavior of C / C-SiC-ZrB_2 carbon-ceramic composites

采用化学气相渗透与先躯体浸渍裂解混合工艺(CVI+PIP),研制了C/C-SiC-ZrB2多元炭陶复合材料,采用化学气相沉积技术(CVD),对所研制的复合材料进行了涂层封孔。采用热力学分析与电弧风洞试验,并借助扫描电镜(SEM)、能谱分析(EDS)、X射线衍射分析(XRD)等手段,研究了其抗烧蚀性能和烧蚀机理。结果表明,ZrB2含量较高的C/C-SiC-ZrB2复合材料具有优异的抗烧蚀性能,经历Ma=6,600 s电弧风洞考核后,线烧蚀率仅为1.0×10-4mm/s。C/C-SiC-ZrB2复合材料的烧蚀包括氧化、挥发(或升华)和机械冲刷,是热/力/化学耦合作用的结果。

The 3D C/C-ZrB2-SiC composites were prepared through chemical vapor infiltration （CVI） and precursor infiltration and pyrolysis （PIP） process. The microstructures and ablation behaviors of the prepared composites were studied. The composition and microstructure of the ablated samples were characterized by arc tunnel test, XRD and SEM, respectively. The results show that the mass ablation rate and linear ablation rate of the composites generally decrease first and then increase with the increase of ZrB2 contents. After ablation at Ma = 6 for 600 s via arc tunnel test, the linear recession rate is only 1.0x 10-4 mm/s. It is found that the ablation of C/C-ZrB2-SIC composites contains oxidation, sublimation and erosion as result of heat, strength and chemical effects to- gether.