A ZrSiO<sub>4sub>/SiC oxidation protective coating for carbon/carbon composites
- 作者：Jia Liu<sup>asup><sup> ; sup><sup>liu176219878@126.comsup> ; Li-Yun Cao<sup>asup> ; Jian-Feng Huang<sup>asup><sup> ; sup><sup>hjfnpu@163.comsup> ; Yu Xin<sup>asup> ; Wen-Dong Yang<sup>bsup> ; Jie Fei<sup>asup> ; Chun-Yan Yao<sup>asup>
- 关键词：Carbon/carbon composites ; ZrSiO4 coating ; Hydrothermal electrophoretic deposition ; Oxidation
- 刊名：Surface and Coatings Technology
- 出版年：2012
- 期刊代码：106_02578972
- 类别：ms
- 出版时间：15 March, 2012
- 卷：206
- 期：14
- 页码：3270-3274
- 文件大小：1195 K
摘要
In order to improve the oxidation resistance of carbon/carbon (C/C) composites, a ZrSiO<sub>4sub> coating on SiC pre-coated C/C composites was prepared by a hydrothermal electrophoretic deposition process. Phase compositions and microstructures of the as-prepared ZrSiO<sub>4sub>/SiC coating were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The anti-oxidation property and failure mechanism of the multi-layer coating were investigated. Results show that hydrothermal electrophoretic deposition is an effective route to prepare crack-free ZrSiO<sub>4sub> outer coatings. The multi-layer coating obviously exhibits two-layer structure. The inner layer is composed of SiC phase and the outer layer is composed of ZrSiO<sub>4sub> phase. The bonding strength between the outer layer coatings and C/C-SiC substrate are 30.38 MPa. The ZrSiO<sub>4sub>/SiC coating displays excellent oxidation resistance and can protect C/C composites from oxidation at 1773 K for 332 h with a mass loss rate of only 0.48 脳 10<sup>鈭?#xA0;4sup> g/cm<sup>2sup>路h. The mechanical properties of the specimens are 84.36 MPa before oxidation and 68.29 MPa after oxidation. The corresponding high temperature oxidation activation energy of the coated C/C composites at 1573-1773 K is calculated to be 119.8 kJ/mol. The oxidation process is predominantly controlled by the diffusion rate of oxygen through the ZrSiO<sub>4sub>/SiC multi-coating. The failure of the coating is due to the formation of penetrative holes between the SiC bonding layer and the C/C matrix at 1773 K.