Vacuumless synthesis of tungsten carbide in a self-shielding atmospheric plasma of DC arc discharge

Abstract

The goal of this paper is to simplify and reduce the cost of manufacturing tungsten carbide. The work presents the results of experimental studies that prove the possibility of synthesizing fine and ultrafine crystalline phases of tungsten carbide in the DC arc discharge plasma ignited in open air by a developed vacuumless technique. The synthesis is implemented in the process of arc discharge burning between the graphite rod (anode) placed inside the cavity of the graphite cathode in the presence of graphite and tungsten powders used as initial precursors. The cathode cavity (reaction zone) is shielded from oxygen by a stream of carbon monoxide and carbon dioxide gases, which are generated during the arc discharge burning in an open air. After studying the influence of main process parameters (parameters of the discharge circuit and graphite electrode's dimensions) and optimizing the system, the authors obtained tungsten carbide phases without impurities of oxide phases. This allows simplifying significantly the technology of tungsten carbides synthesis by excluding the stage of vacuum creation.