Preparation of Fine Carbide Powders by Vapor Phase Reaction (3) ( Synthesis of Tungsten Carbide Powders by WCl6 - C2H4 - H2 System )
김수식Soo Sik Kim, 김한삼han Sam Kim
Abstract
To obtain fundamental informations for fine tungsten carbide powders, the preparation of fine tungsten carbide by vapor phase reaction of WCl_6-C₂H₄-H₂ system has been carried out in the temperature range of 800-1300℃ The effects of reaction conditions on particle size and morphology of tungsten carbide powders have been investigated by utilizing X-ray diffraction, SEM and TEM techniques. The content of WC increased remarkably with increasing the reaction temperature and the maximum content was about 95% at 1100℃ in the condition of the flow rate of argon and H₂ gas 200㎖/min respectively and C₂H₄, gas 15㎖/min. The particle size of the reaction products obtained at 1100℃ is about 0.007㎛ and the shape of WC is spherical. The particle size decrease linearly with increasing reaction temperature. On the other hand, the agglomerate particle size increase linearly with increasing temperature. The lattice parameters a and c increase gradually with increasing reaction temperature.