【摘要】 利用常规化学气相渗透工艺,在针刺炭布预制体中添加3.5%～4.0%Ni/SiO2负载型金属催化剂,以丙烯作碳源气体,在750～900℃下,经过100h的沉积,炭/炭(C/C)复合材料的密度达到1.65g/cm3,其催化沉积炭的速率比不含催化剂时提高了3倍以上。该材料经高温处理后,氧化失重率低,氧化起始温度高。应用扫描电镜(SEM),X射线衍射分析(XRD)和光学显微镜观察了基体炭的形貌,分析了催化沉积炭和抗氧化机理。实验结果证明,用该催化化学气相渗透法制备C/C复合材料,周期短,成本低,抗氧化性能好。更多还原

【Abstract】 By making use of a conventional isothermal chemical vapor infilt ra tion (ICVI) process, silica- supported Ni catalysts with different loading cont ent were loaded onto the c- fiber cloth substrates that were further treated at 750～ 900 ℃ to make high density C/C composites with propylene as carbon sour ce gas. It has been found that the density of the as- prepared C/C composite co uld reach 1.65 g/cm3 in 100 h, and the corresponding catalytic depositing rate w as three times quicker compared with the non- catalytic process. After further high- temperature treatment, the C/C composites show smaller weight loss and hi gher initial oxidation temperature. The surface morphology of the substrate carb on was examined by SEM, XRD and optical microscopy. The mechanisms involved in t he catalytic deposition process and in the oxidation resistance were studied. Th e experimental results have proved that the C/C composites made by the catalytic CVI (CCVI) process has a number of advantages such as short preparation time, l ow cost and high oxidation- resistant.更多还原