The properties of Cf/SiC composites prepared from different precursors
The properties of Cf/SiC composites prepared from different precursors
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DOI：
10.1016/j.ceramint.2014.12.111
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发表时间：
2015-04
影响因子：
5.2
通讯作者：
Bei Yang;Xingui Zhou;Jinshan Yu
中科院分区：
文献类型：
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作者：
Bei Yang;Xingui Zhou;Jinshan Yu
尽管碳化硅材料由于制造协议和成本而在应用上受到限制，但仍具有显着的稳定性和耐磨性。在本文中，研究了两种不同的 SiC 前驱体：1) 2,4,6,8-四乙烯基-2,4,6,8-四甲基环四硅氧烷 V4 和液体聚碳硅烷 (LPVCS) 的混合物，2) 聚碳硅烷 (PCS)。分别通过两种前驱体的渗透和热解制备了三维针刺碳纤维毡增强碳化硅（Cf/SiC）复合材料。这些前体首先通过 FT-IR 和 XRD 进行表征。研究了不同前驱体对复合材料致密化、力学性能和微观结构的影响。结果表明，LPVCS和PCS具有相似的晶体结构和密度。两种不同前体在 FT-IR 中的主要区别在于 LPVCS 中乙烯基的特征吸收峰。虽然由 PCS 制备的复合材料表现出更好的机械性能（弯曲强度高 40%，断裂韧性高 25%），但考虑到环境和操作条件，LPVCS 被证明是更好的前体，通过进一步改性，LPVCS 可能在许多应用中取代 PCS。
Silicon carbide materials have remarkable stability and wear resistance in spite of their limitation in application due to the fabrication protocols and costs. In this article, two different SiC precursors were investigated: 1) a mixture of 2,4,6,8-tetravinyl-2,4,6,8-tetramethyl-cyclotetrasiloxane—V4 and liquid polycarbosilane (LPVCS), 2) polycarbisilane (PCS). Three-dimensional needled carbon fiber felt reinforced silicon carbide (Cf/SiC) composites were fabricated by infiltration and pyrolysis of the two precursors separately. These precursors were first characterized by FT-IR and XRD. The effects of different precursors on densification, mechanical properties and microstructures of the composites were studied. The results showed that LPVCS and PCS had similar crystal structure and density. The main difference between the two different precursors in FT-IR was the characteristic absorption peak of the vinyl group in LPVCS. Though the composites prepared from PCS exhibited better mechanical properties (40% higher in flexural strength and 25% higher in fracture toughness), LPVCS turned out to be a better precursor considering environmental and handling conditions, which may replace PCS in many applications with further modifications.