(1.中南大学 材料科学与工程学院, 长沙 410083；
2. Department of Chemical Engineering, University of Sherbrooke,
Sherbrooke, J1K 2R1, Canada)
摘 要: 用射频感应等离子体将钨粉炭化成碳化钨, 对炭化过后的粉末在氩气保护下, 于1900℃进行烧结处理, 并对在感应等离子体中钨粉被甲烷炭化的反应过程和在高温基体上碳与沉积物进一步反应的机理进行了研究。采用扫描电镜和X射线衍射仪分析了原始钨粉、炭化粉末和反应沉积物的显微组织和成分。 结果表明， 快速炭化反应开始于金属钨粉熔化后, 颗粒尺寸为5μm的钨粉在等离子体中被部分炭化, 完全炭化要靠反应沉积物在高温基体上与碳的进一步反应来实现, 经炭化的钨粉在热处理时存在脱碳现象。
关键字: 钨粉；甲烷； 感应等离子体； 碳化钨； 炭化过程
deposited in radio frequency induction plasma
（1. School of Materials Science and Engineering,
Central South University, Changsha 410083, China；
2. Department of Chemical Engineering,
University of Sherbrooke, Sherbrooke, J1K 2R1, Canada）
Abstract:Radio frequency induction plasma was used to synthesize tungsten carbide directly from metallic tungsten powder. The carburization process of tungsten particles with methane in the induction plasma and the reaction between carbon and deposit on the high temperature substrate were investigated. Carburized tungsten powder was sintered at 1900℃ under the protection of Ar. Scanning electron microscopy and X-ray diffraction were used to analyze the starting tungsten powder, the carburized tungsten powder and the deposit. The results show that rapid carburization of the tungsten powder in the reactive plasma starts when tungsten particles are melted. Within the plasma flame, the tungsten powder with 5μm can only be partially carburized. Completion of the carburization process requires the reaction between involved carbon and the deposit on the substrate at high temperatures. Decarburization phenomenon happens during the heat treatment of the carburized powder.
Key words: tungsten powder； methane； induction plasma； tungsten carbide； carburization process
