Effect of process parameters on induction plasma reactive deposition of tungsten carbide from tungsten metal powder

摘要

Tungsten carbide deposit was made directly from tungsten metal powder through the reaction with methane in radio frequency induction plasma. Effect of major process parameters on the induction plasma reactive deposition of tungsten carbide was studied by optical microscopy, scanning electron microscopy, x-ray diffraction analysis, water dis- placement method, and microhardness test. The results show that methane flow rate, powder feed rate, particle size, re- action chamber pressure and deposition distance have significant influences on the phase composition, density, and micro- hardness of the deposit. Extra carbon is necessary to ensure the complete conversion of tungsten metal into the carbide.