共查询到20条相似文献,搜索用时 109 毫秒
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为提高C/C复合材料的高温抗氧化性能,以聚碳硅烷(PCS)浸渍裂解法和Si,Mo,W粉浆料刷涂反应法在C/C复合材料表面制备SiC-MoSi2-WSi2复合涂层,借助X射线衍射仪、扫描电镜等分析手段,对涂层的微观形貌、组织结构及物相进行分析研究,优化涂层制备工艺,考察了涂层的高温抗氧化性能,分析了抗氧化机理.制备的SiC-MoSi2-WSi2复合涂层厚度200 μm左右,主要由SiC,MoSi2,WSi2构成.1500℃氧化试验结果表明复合涂层的静态氧化失重率较SiC单层涂层降低50%以上,较大地改善了C/C复合材料的抗氧化性能. 相似文献
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为了提高C/C复合材料在高温有氧环境的抗氧化性,在SiC抗氧化涂层防护的基础上,采用气相沉积法及溶胶凝胶吸附冷凝热蒸汽法在C/C复合材料表面制备出了SiC-SiO2/ZrO2-SiC复合涂层。利用扫描电镜、能谱质谱测试及X射线衍射等检测方法对涂层各层进行了分析。结果表明,溶胶吸附ZrCl4蒸汽法制备ZrO2涂层,不仅能够在高温自动修复单层SiC涂层的裂纹缺陷,还起到了在制备外层SiC涂层过程中缓冲应力的作用。这种多层复合涂层在高温下具有良好的抗氧化性,在1 800℃等离子焰动态空气氧化120 s后,计算得出该涂层失重速率仅为0.4 g/(m2·s),表明该涂层具有卓越的抗氧化性。 相似文献
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《合成材料老化与应用》2017,(1)
C/C复合材料高温力学性能优异,但其最大缺点是在高温下会被快速氧化,而在其表面制备抗氧化涂层是提高其使用寿命的最直接有效的方法。该文综述了国内外C/C复合材料抗氧化涂层的材料体系的最新研究成果,根据磷酸盐、硅化物、稀土硅酸盐、硼化物、难熔金属碳化物等各种材料的物理化学性质,分析介绍了各种体系的抗氧化机理。通过总结对比大量涂层体系的抗氧化性能,指出目前研究中存在的问题及高温抗氧化涂层的发展趋势。 相似文献
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X-43A高超音速飞行器C/C热防护涂层结构分析 总被引:1,自引:0,他引:1
《高科技纤维与应用》2015,(4)
介绍了涂层式抗氧化C/C复合材料在美国的研制及其在高超音速飞行器上应用概况,重点是C/C复合材料抗氧化复合涂层的涂层结构、制备工艺和应用评价。C/C复合材料表面化学转化法生成Si C过渡层是美国航天飞行器制备抗氧化涂层的通用方法。MER公司研制的转换法Si C、化学气相沉积Si C和Hf C 3层涂层结构的抗氧化C/C复合材料,其横向压缩性能大于未涂层C/C材料;并成功地应用于X-43A Ma10飞行器2 200℃的临近空间飞行,实现了零氧化烧蚀。 相似文献
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Shangwu Fan Xu Ma Zuo Li Jing Hu Zan Xie Juanli Deng Litong Zhang Laifei Cheng 《Ceramics International》2018,44(1):175-182
A SiCN/borosilicate glass anti-oxidation coating with double-layer structure was designed for C/C aircraft brake materials. The SiCN layer was introduced as transition layer to improve the wettability between borosilicate glass and C/C composites, and the microstructure results indicated that the coating with SiCN inner layer was dense and uniform. The oxidation resistance evaluation of the coated samples was conducted at 800 °C in air for 10 h. The weight loss of SiCN/borosilicate glass coated samples valued ~ 5.66% indicated that the oxidation resistant property of the simple SiCN/borosilicate glass coating was not good, which was mainly due to the relative large viscosity of borosilicate glass at 800 °C. B4C was introduced to add into the outer glass coating to improve the self-healing ability of the coating. After oxidized at 800 °C in air for 10 h, the weight loss of the SiCN/borosilicate glass-B4C coated samples was ~ 2.48%. B4C could consume the oxygen diffused into the coating and the reacted product B2O3 with a better fluidity at 800 °C could effectively heal cracks and pores in the coating to improve the oxidation resistance property. The reaction of B4C oxidized to B2O3 was accompanied with ~ 1.5 times volume expansion, which was also beneficial for the healing of defects. 相似文献
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《Ceramics International》2021,47(22):31251-31258
A modification of the precursor infiltration pyrolysis (PIP) method was explored to prepare the integrated doped ceramic matrix and coating by the added SiC nanowires layer and shape-stabilization process. The epitaxial layer of SiC nanowires provided surficial attachments for the precursor. And the shape-stabilization process aggregated loose ceramic particles into a coating. Then the SiC nanowire-reinforced ZrC–SiC coating-matrix integrated C/C (S/SZ-CZ/C) composite was simply prepared by the modified PIP method. The bonding strength between the coating and matrix of the S/SZ-CZ/C composite was improved. Through the ablation test, the mass and linear ablation rate of the S/SZ-CZ/C composite were 0.46 mg/s and 0.67 μm/s, which were 60.34 % and 74.91 % lower than those of the SiC nanowire-reinforced C/C–ZrC (S/CZ/C) composite, respectively. The integration of the coating and matrix enabled the formation of a continuous oxide layer of molten SiO2 and ZrO2 in the ablation process, which helped to block the oxygen and heat during the ablation test. Thus the ablation resistance of the materials was systematically and effectively improved. 相似文献
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C/C复合刹车材料及防氧化技术研究进展 总被引:3,自引:0,他引:3
介绍了C/C复合刹车材料的发展进程,国际上主要的飞机刹车机轮公司C/C复合材料及防氧化涂料的生产技术和工艺特点,C/C复合刹车材料的特性以及国内C/C复合刹车材料制备和防氧化技术的部分情况。 相似文献
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《Ceramics International》2022,48(3):3206-3215
B4C modified HfB2-SiC coating for C/C substrate was designed to expand the application of HfB2-SiC based coating in low-medium temperature environment. The oxidation protection behavior of HfB2-SiC based ceramic coatings with and without B4C at 1073, 1273 and 1473 K was tested and analyzed. The experimental results reveal that the oxidative damage of HfB2-SiC coated C/C reduces by over 20% after introducing B4C, which may be due to the protection of borosilicate glass with more suitable viscosity during oxidation. Meanwhile, B4C can improve the oxidation protection ability of HfB2-SiC coating best at 1473 K. And the introduction of B4C can reduce the mass loss of HfB2-SiC coated C/C sample by 77.6% after oxidation for 58 h at 1473 K. The fluidity of glass film becoming better with temperature-rising, and the fluid borosilicate glass layer makes the coated samples have the best anti-oxidation properties at 1473 K among these three temperatures. 相似文献
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《Ceramics International》2022,48(15):21709-21716
The cyclic ablation resistance of coated carbon/carbon (C/C) composites play crucial roles in their further engineering applications and development due to the cyclic ablation environment accompanied by rapid heating and cooling and high-speed heat flow scouring, which can reflect the performance stability of the coating. In this research, a (SiC/HfC)4/SiC (SHS) multi-layer coating was prepared on C/C composites. Compared with single layer (SiC and HfC coating) coated sample, the mass and linear ablation rate of SHS coated sample after three ablation cycles (60 s × 3) were only 0.64 mg/s and 0.53 μm/s, respectively. This is mainly because the introduction of many interfaces inhibits the propagation of cracks, the irregular cracks region only exists in the outer layer. Besides, the oxide layer with dense structure was formed near the C/C substrate, which could prevent oxygen from penetrating into the coating and continue to play a protective role. 相似文献
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《Journal of the European Ceramic Society》2022,42(14):6435-6444
A chromium carbide (Cr-C) coating in-situ formed on the C/C substrate is successfully prepared by a novel reactive wetting strategy. The interfacial microstructure and oxidation resistance of coated C/C composites are investigated in detail. The as-prepared coating mainly consists of Cr23C6 and Cr7C3, forming a tight joining with the C/C substrate. Compared to uncoated samples, the oxidation weight loss of coated C/C composites is substantially reduced at high temperatures. Furthermore, the hardness of coated C/C composites is significantly increased, enhancing their ability to resist external damage. This reactive wetting strategy can also be used to prepare uniform coatings on C/C composites with complex grooved structure or large size. Surprisingly, coated C/C composites possess a low weight gain of 3.7% due to thin coating (< 10 µm), which can maintain their advantage of low density. 相似文献
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《Journal of the European Ceramic Society》2022,42(14):6425-6434
New method to prepare Si-SiC coating on C/C composites by laser cladding (LC-Si-SiC) was established to improve the laser ablation resistance of the coating. Results showed that the LC-Si-SiC coating had lower roughness, better mechanical properties and superior laser-ablation resistance compared with the Si-SiC coating fabricated by the traditional coating preparation process: pack cementation (PC-Si-SiC). Due to the shorter heat treatment and less Si infiltration, the flexural strength of the LC-Si-SiC coated sample was 111.32 MPa, which was 144% higher than that of the PC-Si-SiC coated sample. Confirmed by finite element simulation, the LC-Si-SiC coating exhibited better laser-ablation resistance because of the “sweating cooling” mechanism. Under 23.89 MW?m?2 ablation for 7 s, the surface temperature of the LC-Si-SiC coated sample was 3046 K, which was 157 K lower than that of the PC-Si-SiC, causing the mass loss rate of the LC-Si-SiC coating (0.10%) was only 45.45% of the PC-Si-SiC coating. 相似文献
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《Journal of the European Ceramic Society》2023,43(11):4636-4644
To maintain the thermal stability of SiC nanowires during SiC coating fabrication process, carbon and SiC double protective layers were covered on the surface of nanowires. And SiC nanowires with double protective layers toughened SiC coating were prepared by pack cementation. The results showed that after introducing the SiC nanowires with double protective layers, the fracture toughness of the SiC coating was increased by 88.4 %. The coating protected C/C for 175 h with a mass loss of 3.67 %, and after 51 thermal shock cycles, the mass losses of the oxidized coating were 3.96 %. The double protective layers are beneficial to improve the thermal stability of nanowires, leading to good fracture toughness and thermal shock resistance of SiC coating. SiC nanowires consume the energy of crack propagation by fracture, pullout and bridging, leading to an increase in fracture toughness. 相似文献