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采用原位反应法在三维碳纤维编织体(简称:RB)的纤维表面制得SiC涂层,通过 XRD、SEM、等温氧化失重和非等温热重分析等测试手段研究了制备方法对SiC涂层均匀性 的影响,并对SiC涂层/碳纤维编织体(简称:CB)材料在等温和非等温条件下,氧化反应的 动力学和反应机理进行了研究.结果表明:SiC涂层均匀、完整地涂覆于编织体内外各纤维表 面;材料等温氧化反应的机理为第一阶段反应控制,第二阶段扩散和反应共同控制;材料的非 等温氧化过程呈现自催化特征,氧化机理为随机成核,氧化动力学参数为:lgA=9.615min-1; Ea=201.73kJ·mol-1.
In situ reaction method was used to fabricate SiC coating on the surface of three-dimensional carbon fiber braid (RB) fiber. The effects of preparation method on the properties of SiC coating Uniformity and the kinetics and reaction mechanism of the oxidation reaction of SiC coated / carbon fiber braid (abbreviated: CB) under isothermal and non-isothermal conditions were studied.The results show that the SiC coating is uniformly and completely The mechanism of the isothermal oxidation reaction is controlled by the first stage reaction and controlled by the second stage diffusion and reaction. The non-isothermal oxidation process of the material exhibits autocatalytic characteristics. The oxidation mechanism is random nucleation, Oxidation kinetics parameters: lgA = 9.615min-1; Ea = 201.73kJ · mol-1.