熔盐反应法在碳纤维表面制备TaC涂层

Preparation of TaC Coating on the Surface of Carbon Fibers by Molten Salt Reaction Method

在由NaCl、KCl和KF组成的混合盐体系中,利用熔盐反应法在碳纤维表面成功地制备了TaC涂层。研究了反应温度对TaC涂层相组成、表面形貌以及涂层厚度的影响。结果表明,在950-1200℃范围内能在碳纤维表面制备TaC涂层,并且随着反应温度的升高,TaC涂层的厚度增加,涂层的颗粒尺寸增大,均匀程度下降。TaC涂层对碳纤维抗氧化能力的改善在很大程度上取决于涂层质量以及涂层与碳纤维基体的结合状态。在1000℃保温5h制备的TaC涂层连续、均匀而致密,且与基体的结合较好,涂层后碳纤维的起始氧化失重温度从原来的450℃升高到650℃左右。

The TaC coating is prepared successfully on the carbon fibers by molten salt reaction method in the salt mixture composion of NaCI, KCl and KF. The influences of reaction temperature on phase composition, surface morphology and thickness of TaC coating are studied. The results show that TaC coating can be prepared on the carbon fibers at 950-1200℃. With the increase of reaction temperature, the thickness of TaC coating is increased. The crystallites of TaC are small at lower temperature, while larger crystallites of TaC are formed at higher temperature and distribute inhomogeneously. The improvement of oxidation resistance of the carbon fibers by TaC coating is primarily dependent on the combination state between coating and carbon fiber matrix. A continuous, homogeneous and dense TaC coating is formed on the surface of the carbon fibers after holding for 5h at 1000℃, and the coating adheres well with the carbon fiber matrix. After coated with the TaC coating, the oxidative weight loss initiation temperature of the carbon fibers is increased from 450℃ to about 650℃.