Synthesis of Vanadium Carbide by Mechanical Activation Assisted Carbothermic Reduction
Z.I. Zaki, Mohamed Elsadek, H.H. Ali, Hesham M. Ahmed
Abstract
Vanadium carbide is known, for its hardness and other unique properties, as a refractory material. The synthesis of vanadium carbide is always associated with the utilization of expensive active metals, such as aluminum, calcium and magnesium, as a reducing agent to extract the vanadium metal from its corresponding oxide, followed by carbidization. The carbidization of reduced vanadium requires a complicated process and elevated temperature. Mechanical activation to synthesize vanadium carbide from its corresponding oxide and carbon source represents a promising, straightforward and less energy-intensive route. In the present study, vanadium carbide is synthesized by the carbothermic reduction of a mechanically activated mixture of V2O5 and carbon black as reducing agents without any additives. The reduction process is monitored by means of thermogravimetric analysis. The reduction products are characterized by X-ray diffraction and field emission scanning electron microscope. It is found that V8C7 with an average crystallite size of 88 nm can be synthesized from a V2O5-C mixture after milling for 15 h and further heating at 1050 °C for 1 h in an inert atmosphere.