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Oxidation behavior of carbon/carbon-boron nitride composites fabricated by additives and chemical vapor infiltration
Ceramics International ( IF 5.1 ) Pub Date : 2019-03-01 , DOI: 10.1016/j.ceramint.2018.11.108
Peng Xiao , Zeyan Liu , Zhi Chao Li , Bengu Zhang , Zhuan Li , Yang Li

Abstract Carbon/carbon-boron nitride (C/C-BN) composites were manufactured by adding hexagonal boron nitride (h-BN) powders into carbon fiber preform and a subsequent chemical vapor infiltration (CVI) process for deposition of pyrolytic carbon (PyC). Microstructure and oxidation behavior of carbon/carbon composites with 9 vol% h-BN (C/C-BN9) were studied in comparison to carbon/carbon (C/C) composites. Results showed that with the addition of h-BN powders, a regenerative laminar (ReL) PyC with higher texture was achieved. Note that the introduction of h-BN powder make great contributes to graphitization degree of PyC, leading to larger oxidation activation energy. Moreover, under an air atmosphere, h-BN started to oxidize above 800 °C, and generated molten boron oxide (B2O3) which prohibited oxygen diffusion by filling in pores, cracks and other defects. As these reasons mentioned above, after oxidation tests under an air atmosphere, mass losses of C/C-BN9 composites were lower than that of C/C composites at all test temperatures (600–900 °C), indicating that the oxidation resistance of C/C-BN9 composites is better than that of C/C composites.

中文翻译:

添加剂和化学气相渗透制备的碳/碳-氮化硼复合材料的氧化行为

摘要 通过将六方氮化硼 (h-BN) 粉末添加到碳纤维预制棒中,然后通过化学气相渗透 (CVI) 工艺沉积热解碳 (PyC) 来制备碳/碳-氮化硼 (C/C-BN) 复合材料。 . 与碳/碳 (C/C) 复合材料相比,研究了含有 9 vol% h-BN (C/C-BN9) 的碳/碳复合材料的微观结构和氧化行为。结果表明,通过添加 h-BN 粉末,实现了具有更高质地的再生层流 (ReL) PyC。注意 h-BN 粉末的引入对 PyC 的石墨化程度有很大贡献,导致更大的氧化活化能。此外,在空气气氛下,h-BN 在 800 °C 以上开始氧化,生成熔融的氧化硼 (B2O3),通过填充孔隙阻止氧气扩散,裂纹和其他缺陷。由于这些原因,在空气气氛下进行氧化试验后,C/C-BN9 复合材料在所有试验温度(600-900 ℃)下的质量损失均低于 C/C 复合材料,表明C/C-BN9复合材料优于C/C复合材料。
更新日期:2019-03-01
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