共查询到20条相似文献,搜索用时 11 毫秒
1.
《Ceramics International》2017,43(11):8208-8213
In order to improve the oxidation behavior of carbon/carbon composites in a wide range of temperature, a new SiC/glaze-precursor coating was developed.The SiC layer was produced by slurry and sintering, while the glaze precursor layer was prepared by slurry and drying. The microstructures and phase compositions of the coating were analyzed by SEM and XRD, respectively. The oxidation resistance of the coated composites was investigated using both isothermal and temperature-programmed thermogravimetric analysis in the temperature range from room temperature to 1600 °C. The results showed that the oxidation behavior of the coating was mainly controlled by the diffusion of oxygen during the test.The coating showed excellent oxidation resistance and self-healing ability in a wide range of temperature. 相似文献
2.
Li Ke-Zhi Lan Feng-Tao Li He-Jun Shen Xue-Tao He Yong-Gang 《Journal of the European Ceramic Society》2009,29(9):1803-1807
In order to improve the oxidation resistance of carbon/carbon composites at intermediate temperatures, a novel double-layer SiC/indialite coating was prepared by a simple and low-cost method. The internal SiC transition layer was prepared by pack cementation and the external indialite glass–ceramic coating was produced by in situ crystallization of ternary MgO–Al2O3–SiO2 glass. The microstructures and morphologies of coating were determined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). Oxidation resistance of the as-coated C/C composites was evaluated in ambient air at temperature from 800 °C to 1200 °C. Nearly neglectable mass loss was measured after 100 h isothermal oxidation test, indicating that SiC/indialite coating possesses excellent oxidation protection ability. The as-coated samples have a good thermal shock resistance and no obvious damage was found in the coating even after suffered more than 11 thermal cycles between test temperature and room temperature. The oxidation protection mechanism of this coating was also discussed. 相似文献
3.
《Ceramics International》2022,48(2):1740-1744
A novel SiC coating with a relatively high crack resistance property (crack extension force (GC): 12.0 J·m?2) and outstanding thermal shock resistance was achieved merely by pack cementation. Compared with the conventional SiC coating with Al2O3 addition (AOSC2), SiC coating with Al–B–C additions (ABSC2) possesses refined and denser microstructure owing to different effects in promoting SiC densification under different additions. Therefore, the improvement in microstructures results in superior mechanical capabilities, antioxidation performance (900 °C), and thermal shock resistance (between 1500 °C and room temperature). 相似文献
4.
Yonglong Xu Wei Sun Xiang Xiong Zizhang Zhan Tian Tian Yuntian Chen Zheng Peng 《Journal of the European Ceramic Society》2018,38(13):4363-4372
Nitrogen-modified ZrC-SiC coatings were prepared by thermal evaporation, in situ reaction, and nitriding process, and the microstructure and ablation property of the coatings were studied. The results showed that nitrogen atoms could replace the carbon atoms and fill the vacancies of ZrC. In addition, the interface of the ZrC phase was optimized. The nitrogen atom solid solution was limited on the coating surface, and the interior of the coating was composed of high-melting point ZrC and SiC ceramics. The ablation test showed a reduction in the ablation rate of the coating after nitriding due to the formation of a dense ZrO2 layer. 相似文献
5.
《Ceramics International》2016,42(16):18411-18417
SiC coating with a thickness of 50–70 µm was prepared on the surface of C/C composites by in-situ reaction method. The SiC coated C/C composites were then tested in a wind tunnel where a temperature gradient from 200 to 1600 °C could be obtained to investigate their erosion behavior. The results of wind tunnel test indicated that the service life of C/C composites was prolonged from 0.5 to 44 h after applying the SiC coating. After the wind tunnel test, three typical oxidation morphologies, including glassy SiO2 layer, porous SiO2 layer and clusters of honeycomb-like SiO2 grains, were found on the SiC coated C/C composites. With the decrease of oxidation temperature, the amount of glassy SiO2 declined and the thermal stress increased, which induced the cracking followed by the degradation of the SiC coating. 相似文献
6.
Guanghui Feng Hejun Li Xiyuan Yao Hang Zhou Yulan Yu Jinhua Lu 《Journal of the European Ceramic Society》2021,41(6):3207-3218
HfC-TaC/HfC-SiC alternate coatings with different sublayer thicknesses were fabricated on SiC-coated carbon/carbon composites by supersonic atmosphere plasma spraying. Their ablation resistance was studied under oxyacetylene torch and compared with monolayered HfC-TaC coating. The alternate coating with 6 spray cycles of HfC-TaC and 3 spray cycles of HfC-SiC sublayers exhibited the best ablation performance as confirmed by the integral coating morphology and the lowest ablation rates. A dense oxide layer acting as an oxygen insulator and the release of thermal stress induced by the formation of dendritic cracks are thought to be responsible for its great ablation resistance. For the alternate coating with 4 spray cycles of HfC-TaC and 2 spray cycles of HfC-SiC sublayers, exfoliation occurred at the interface of two adjacent sublayers, leading to violent evaporation of exposed HfC-SiC sublayer. 相似文献
7.
8.
ZrC ablation protective coating for carbon/carbon composites 总被引:2,自引:0,他引:2
Wei Sun Bai-yun Huang Guo-dong Li Hong-bo Zhang Zhao-ke Chen Xiang-Lin Zheng 《Carbon》2009,47(14):3368-571
A zirconium carbide (ZrC) protective coating was deposited on carbon/carbon (C/C) composites by atmospheric pressure chemical vapor deposition. The phase compositions, surface and cross-section microstructures, and anti-ablative properties of the coatings were investigated. Results show that the method is an effective route to prepare a dense and thick ZrC coating on C/C composites. The coating can effectively protect C/C composites from ablation for 240 s in an oxy-acetylene torch system with a mass ablation rate of 1.1 × 10−4 g/cm2 s and a linear ablation rate of 0.3 × 10−3 mm/s. 相似文献
9.
10.
Kai-Tong Wang Li-Yun Cao Jian-Feng Huang Jie Fei 《Journal of the European Ceramic Society》2013,33(1):191-198
To protect carbon/carbon (C/C) composites against oxidation, a mullite coating was prepared on SiC precoated C/C composites by a hydrothermal electrophoretic deposition process. The phase composition, microstructure and oxidation resistance of the prepared mullite/SiC coatings were investigated. Results show that hydrothermal electrophoretic deposition is an effective route to achieve crack-free mullite coatings. The mullite/SiC coating displays excellent oxidation resistance and can protect C/C composites from oxidation at 1773 K for 322 h with a weight loss rate of only 4.89 × 10?4 g/cm2 h. The failure of the multi-layer coatings is considered to be caused by the volatilization of silicate glass layer, the formation of microholes and microcracks on the coating surface and the formation of penetrative holes between the SiC bonding layer and the C/C matrix at 1773 K. The corresponding high temperature oxidation activation energy of the coated C/C composites at 1573–1773 K is calculated to be 111.11 kJ/mol. 相似文献
11.
12.
A hot-pressing reactive sintering (HPRS) technique was explored to prepare SiC coating for protecting carbon/carbon (C/C) composites against oxidation. The microstructures of the coatings were analyzed by X-ray diffraction and scanning electron microscopy. The results show that, SiC coating obtained by HPRS has a dense and crack-free structure, and the coated C/C lost mass by only 1.84 wt.% after thermal cycles between 1773 K and room temperature for 15 times. The flexural strength of the HPRS-SiC coated C/C is up to 140 MPa, higher than those of the bare C/C and the C/C with a SiC coating by pressure-less reactive sintering. The fracture mode of the C/C composites changes from a pseudo-plastic behavior to a brittle one after being coated with a HPRS-SiC coating. 相似文献
13.
《Carbon》1987,25(4):551-557
The oxidation behavior of C/C composite sheet materials in air has been studied over a wide range of temperature. Gasification was detectable at around 500°C and above about 900°C, under the flow conditions used in the experiments, the overall rates of gasification were controlled by gas phase diffusion. The presence of catalysts reduced the temperature for the onset of gasification but had no effect on the kinetics in the diffusion-controlled region. Borate-based coatings containing refractory particulates and silicon carbide coatings sealed with borates have been found capable of protecting C/C composites against air oxidation for extended periods to temperatures of at least 1200°C. 相似文献
14.
Lei Zhou Qiangang Fu Dou Hu Yalong Wei Mingde Tong Jiaping Zhang 《Journal of the European Ceramic Society》2021,41(1):194-203
To reduce the influence of coating preparation on the mechanical properties of carbon/carbon composites and further improve the antioxidant properties of the coating, a SiC-Si coating was fabricated on carbon/carbon composites by gaseous silicon infiltration (GSI-SiC-Si). For comparison, a SiC-Si coating was also prepared by pack cementation (PC-SiC-Si). A comparative investigation showed the GSI-SiC-Si coating possesses relative lower roughness, better mechanical and anti-oxidation properties. The GSI-SiC-Si coating samples maintained 87.8 % flexural strength of bare C/C composites, while the C/C substrate was severely siliconized in PC-SiC-Si coating samples. The GSI-SiC-Si coating samples could undergo 30 thermal cycles between 1773 K and room temperature and effectively protect C/C composites from oxidation at 1773 K for more than 500 h without weight loss. 相似文献
15.
High temperature oxidation resistance of Y2O3 modified ZrB2-SiC coating for carbon/carbon composites
Hanchun Ma Qiang Miao Wenping Liang Yangyang Liu Hao Lin Hairui Ma Shiwei Zuo Lin Xue 《Ceramics International》2021,47(5):6728-6735
To protect carbon/carbon (C/C) composites from oxidation at high temperature, Y2O3 modified ZrB2-SiC coating was fabricated on C/C composites by atmospheric plasma spraying. The microstructure and chemical composition of the coatings were characterized by SEM, EDS, and XRD. Experiment results showed that the coating with 10 wt% Y2O3 presented a relatively compact surface without evident holes and cracks. No peeling off occurred on the interface between the coating and substrate. The ZSY10 coating underwent oxidation at 1450 °C for 10 h with a mass loss of 5.77%, while that of ZS coating was as high as 16.79%. The existence of Y2O3 played an important role in inhibiting the phase transition of ZrO2, thus avoiding the cracks caused by the volume expansion of the coating. Meanwhile, Y2SiO5 and ZrSiO4 had a similar coefficient of thermal expansion (CTE), which could relieve the thermal stress inside the coating. The ceramic phases Y2SiO5, Y2Si2O7 and ZrSiO4 with high thermal stability and low oxygen permeability reduced the volatilization of SiO2. 相似文献
16.
Nano-SiC (SiCn) coating was deposited on SiC pre-coated C/C composites by a hydrothermal electrophoretic deposition. The phase compositions, surface and cross-section microstructures, and anti-oxidation properties of the multilayer coatings were investigated. Results show that hydrothermal electrophoretic deposition is an effective route to prepare smooth and homogeneous SiCn coating on SiC-C/C composites. The as-prepared SiCn/SiC multilayer coatings can effectively protect C/C composites from oxidation in air at 1773 K for 202 h with a weight loss of 0.79% and at 1873 K for 64 h with a weight loss of 1.3%. 相似文献
17.
18.
19.
SiC coating was deposited on carbon/carbon (C/C) composites by chemical vapor deposition (CVD). The effects of elevated temperatures on tribological performance of SiC coating were investigated. The related microstructure and wear mechanism were analyzed. The results show that the as-deposited SiC coating consists of uniformity of β-SiC phase. The mild abrasive and slight adhesive wear were the main wear mechanisms at room temperature, and the SiC coating presented the maximum friction coefficient and the minimum wear rate. Slight oxidation of debris was occurred when the temperature rose to 300?°C. As the temperature was above 600?°C, dense oxide film formed on the worn surface. The silica tribo-film replaced the mechanical fracture and dominated the frication process. However, the aggravation of oxidation at elevated temperatures was responsible for the decrease of friction coefficient and the deterioration of wear rate. The SiC coating presented the minimum friction coefficient and the maximum wear rate when the temperature was 800?°C. 相似文献