以金属钽粉为钽源,采用原位反应法在炭纤维表面成功制备出连续的TaC涂层,研究了涂层炭纤维的相组成、微观形貌和抗氧化性能,并探究了炭纤维表面连续TaC涂层的形成机理。结果表明,在温度为1000~1400℃时能在炭纤维表面制备出TaC涂层,反应温度和时间显著影响涂层厚度以及涂层与炭纤维基体的结合性能;反应温度为1200℃时制备的涂层均匀致密,与炭纤维基体结合较好,涂覆TaC涂层后炭纤维的起始氧化温度提高了200℃。从动力学角度分析了TaC涂层的生长机理,结果表明Ta原子沿炭纤维轴向发生表面扩散,Ta原子的表面扩散行为是连续TaC涂层形成的关键因素。
Continuous TaC coating was successfully prepared on the surface of carbon fibers using tantalum powders as raw materials via in-situ reaction. The composition, morphology and oxidation resistance of TaC-coated carbon fibers were investigated, and the formation mechanism of these continuous TaC coatings on carbon fibers was further studied. The results showed that TaC coating was obtained at the temperature of 1000 ~ 1400 ℃ and the reaction temperature and time have significant effect on the thickness of TaC coating and the combination state between TaC coating and carbon fiber matrix. The TaC coating prepared at 1200 ℃ is uniform and dense, which is adheres well with carbon fiber matrix. After the coated with TaC coating, the initial oxidation temperature of carbon fibers increases by 200 ℃. Besides, the formation mechanism of TaC coating was proposed from a point view of dynamic. It indicates the surface diffusion of Ta along the axial direction of carbon fibers, which is the critical factor for the formation of continuous TaC coating.