C/C复合材料表面TaC涂层的制备和生成机制

Preparation and Formation Mechanism of TaC Coating on Carbon/Carbon Composites

摘要:

报道了一种在C/C复合材料基体上制备抗烧蚀TaC涂层的新方法。采用红外光谱、XRD及SEM表征了生成TaC涂层的Ta源：TaO2F·rH2O·TaF5。采用SEM观察了不同温度下转变生成的TaC涂层的形貌。在1200 ℃高温热处理，TaC涂层形貌为细颗粒状，在1800 ℃高温热处理后，TaC涂层为柱状晶。TaC的生成机制为：TaO2F·rH2O·TaF5高温分解凝聚生成的Ta2O5沉积在C/C复合材料基体表面，碳原子在Ta2O5中扩散反应生成TaC，TaC涂层形貌可由生成Ta2O5的凝聚成核理论解释

Abstract:

A new technology for preparation of TaC coating on Carbon/carbon composites is reported. TaC was turned from TaO2F·rH2O·TaF5, which was characterized by FITR, XRD and SEM. The morphologies of TaC coating at different temperatures were observed by SEM. At 1200 ℃, the TaC coating shows the particular form. When the heat treatment temperature increased to 1800 ℃, the TaC coating was mainly columnar. The formation mechanism of TaC is that Carbon atom diffuse into Ta2O5 deposit, which is coming from TaO2F·rH2O·TaF5 and reacted into TaC at high temperature. The morphology of TaC coating can be interpreted by the theory of Ta2O5 deposited nucleation