溶胶-凝胶法制备锆先驱体改性C/C复合材料  

C/C composites modified by a sol gel based zirconium precursor

作　　者：杨旭堃[1] 刘辉[1] 迟伟东[1] 于建民[1] 许志俊[1] 

机构地区：[1]北京化工大学材料科学与工程学院碳纤维及功能高分子教育部重点实验室,北京100029

出　　处：《北京化工大学学报（自然科学版）》2012年第5期42-48,共7页Journal of Beijing University of Chemical Technology(Natural Science Edition)

摘　　要：采用溶胶-凝胶法合成了锆先驱体,进一步制备了ZrC改性C/C复合材料,研究了锆凝胶在热处理过程中结构的变化。结果表明,锆凝胶在N2条件下的热分解过程主要为结合水的脱除和羧酸盐的分解;900℃下锆凝胶的失重率为43.88%,灰分组成为ZrO2和C。C/C-ZrO2复合材料经1600℃处理得到C/C-ZrC,ZrC颗粒在材料中分散均匀且呈梯度分布,平均粒径约为28 nm,锆元素质量分数(以ZrO2计)约为10%;C/C-ZrC复合材料经1000℃氧化,表面出现能够阻止氧扩散的白色ZrO2氧化膜;C/C-ZrC复合材料的氧化速率比C/C复合材料降低了40.03%,起始氧化温度比C/C复合材料提高了约300℃,材料的抗氧化性能得到明显的改善。A zirconium precursor made by a sol-gel method has been used to prepare C/C-ZrC composites. A zirconium-containing gel was prepared and its structural evolution was studied during heat treatment. Pyrolysis of the gel in nitrogen resulted in a two-stage decomposition-removal of bound water followed by decomposition of carboxylate. The weight loss of the zirconium-containing gel was 43.88% at 900 ℃, with the formation of ZrO2 and C. Treated at 1600 ℃ , the C/C-ZrO2 composites transformed into C/C-ZrC. The particles of ZrC, which had an av- erage particle size of 28 nm, were scattered uniformly with a Zr （ZrO2） mass fraction of 10%. Oxidation tests showed that a white ZrO2 film preventing the diffusion of oxygen was formed on the surface of the C/C-ZrC composites. Compared with C/C composites, the oxidation protection of the C/C-ZrC composites, which have a 40.03% lower oxidation rate and an initial oxidation temperature about 300 ℃ higher than the corresponding values for C/C composites, was improved significantly.

关 键 词：C/C复合材料 溶胶-凝胶法 抗氧化 ZRC 

分 类 号：TB332[一般工业技术—材料科学与工程]