Crystal growth of tungsten during hydrogen reduction of tungsten oxide at high temperature

作     者：吴湘伟 罗劲松 陆必治 谢晨辉 皮志明 胡茂中 徐涛 吴国根 余志明 易丹青 

作者机构：School of Materials Science and EngineeringCentral South University Zhuzhou Cemented Carbide Group Corp.Ltd. 

出 版 物：《中国有色金属学会会刊：英文版》 (Transactions of Nonferrous Metals Society of China)

年 卷 期：2009年第19卷第S3期

页      面：785-789页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

主　　题：coarse grain tungsten powder hydrogen reduction of tungsten oxide crystal growth partial pressure 

摘      要：Crystal growth of tungsten during hydrogen reduction of tungsten oxide (WO3) to prepare coarse grain tungsten powder at high temperature (950 ℃) was studied. The phase composition and morphologies of products were investigated by means of XRD and SEM. The results show that the reduction sequence of hydrogen reduction of WO3 is WO3→WO2.9→W18O49→WO2→W. The step of WO2→W is the critical step which determines the grain size of tungsten powder. The partial pressure (pH2O/pH2) of H2O within powder layer shows strong effect on the nucleation and grain growth of tungsten. By increasing the pH2O/pH2 within powder layer, well-developed coarse grain tungsten powder with particle size above 15 μm is obtained. After carburizing, the powder can be used to produce ultra-coarse grain cemented carbide with grain size above 5 μm.