Surface coating of microparticles with tungsten carbide by using the barrel sputtering system

We studied the coating of microparticles with tungsten carbide using a sputtering system with barrel-type powder sample holder (the barrel sputtering system). In order to find suitable sputtering conditions using the system, tungsten carbide was coated on a glass plate under various desired methane fractions, total pressures and RF powers. According to the XRD analysis on the fabricated films, the desired parameter is attained at a methane fraction of 5%, a total pressure of 1.5 Pa, and an RF power of 100 W. Surface coating of polymer microparticles with a WC layer was performed under this condition. Scanning electron microscope and energy-dispersion X-ray spectrum measurement show that the surface of the microparticle is uniformly coated with a thin WC layer.