3D C<sub>f</sub>/SiC抗高温氧化复合材料的制备及其构件的工程试验

3D C_f/SiC抗高温氧化复合材料的制备及其构件的工程试验

摘要: 采用低分子量聚碳硅烷(PCS)通过先驱体浸渍裂解(PIP)工艺、化学气相沉积(CVD)和粉末烧结技术相结合制备了3D C_f/SiC抗高温氧化复合材料。运用FTIR、¹H-NMR、凝胶渗透色谱法(GPC)、热失重-差热(TGA-DTA)、X射线衍射仪(XRD)和透射电子显微镜(TEM)等手段研究了低分子量PCS的结构及其无机化过程。结果表明: PCS的主要结构为—Si(CH₃,H)—CH₂—n,数均分子量为420,陶瓷化产率为70％左右,在1 200 ℃时基本转化为微晶态的β-SiC;3D C_f/SiC复合材料及其构件具有较好的耐高温氧化性能。

Abstract: 3D C_f/SiC anti-high temperature oxidation composites were prepared with low-molecular polycarbosilane (PCS) via precursor infiltration and pyrolysis (PIP) process, chemical vapor deposition (CVD) and powder sintering technology.FTIR, ¹H-NMR, gel permeation chromatography (GPC), TGA-DTA, XRD and TEM were used to research the structure and inorganic process of low-molecular weight PCS.Results show that the main structure of PCS may be (-Si(CH₃, H)-CH₂-n, the number average molecular weight of PCS is 420, its ceramic yield is approximately 70%, and PCS translates into β-SiC micro-crystal at 1 200 ℃.3D C_f/SiC composites and their members show good performance of anti-high temperature oxidation.