SiO_2涂层/三维碳纤维编织体材料的氧化动力学和机理研究  

Study of Oxidation Kinetics and Mechanism of SiO_2 Coating/3-D Carbon Fiber Braid

作　　者：高朋召[1] 王献忠[2] 王红洁[3] 金志浩[3] 肖汉宁[1] 

机构地区：[1]湖南大学材料科学与工程学院,长沙410082 [2]萍乡高等专科学校,萍乡337055 [3]西安交通大学材料强度国家重点实验室,西安710049

出　　处：《硅酸盐通报》2006年第3期20-24,共5页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(90305001).

摘　　要：采用溶胶-浸渍法,在三维碳纤维编织体的纤维表面涂覆SiO2涂层,通过XRD、SEM、等温氧化失重和非等温TG-DTG等测试手段研究了制备方法对涂层完整性的影响,并对涂层/编织体材料(CB)氧化反应的动力学和机理进行了系统研究。结果表明:采用该方法所得到的涂层均匀完整,与纤维表面结合良好;等温条件下,材料失重低于70%时,定温下,其失重率与氧化时间呈线性关系,反应速率常数随温度的升高而增大。材料的氧化过程随温度升高可分为2个阶段:第1阶段为反应控制,第2阶段为扩散和反应共同控制,分界点为600℃;非等温条件下,材料的氧化过程呈现自催化特征。The reaction kinetics and mechanism of oxidation reaction of SiO2 coating/3-D braided carbon fiber prepared by the sol-dipping method were studied systemly through XRD, SEM, isothermal weight-loss and non-isothermal TG-DTG methods. The results showed that the coating was coated symmetrically and combined well with fiber surface; In isothermal condition, when percent of weight loss was lower than 70%, the weight loss versus oxidation time showed liner relation and the reaction rate constant increased with the increase of temperature, the oxidation process was reaction-controlled in the first oxidation step, gas diffusion and chemical reaction controlled in the second oxidation step, demarcation point was 600℃ ; In non-isothermal condition, the oxidation nronerties of CB exhibited a self-catalytic characteristic.

关 键 词：溶胶-浸渍法 三维碳纤维编织体 氧化动力学 反应机理 

分 类 号：TQ427.6[化学工程] O643.11[理学—物理化学]