Synthesis and characterization of WC-Co nanosized composite powders with in situ carbon and gas carbon sources

This study presented nanosized WC-Co composite powders synthesized using a one-step reduction-carbonization process with a combination of CH4/H-2 as a gas carbon source and soluble starch as an in situ carbon source. The results of carbon analysis and X-ray diffraction revealed that WC-Co nanocomposite powders with a pure WC and Co phase could be obtained at 1100 A degrees C after 0.5 h. A higher gas flow ratio of CH4/H-2 during the reduction-carbonization process led to a higher total carbon content of the sample. A field emission scanning electron microscope confirmed that the particles in the WC-6 wt% Co composite powders had the lowest average size of 43 nm with equiaxed shapes. A sintering neck was observed in the WC-3 wt% Co composite powders whereas faceted particles were found in the WC-12 wt% Co composite powders. Moreover, this method has advantages of simple processing, rapid synthesis and good applicability in potential industry application.