Effect of Dielectric Liquid on Characteristics of WC-Co Powder Synthesized Using EDM Process

This research used electrical discharge machining (EDM) to synthesize nanocrystalline powder from scrap cemented tungsten carbide (WC-Co). The effect of dielectric liquid (deionized water, ethanol and kerosene) and process parameters on the dimensional and structural characteristics of debris was studied. The results show that, with respect to the amount of powder synthesized in dielectric medium, deionized water performs better than ethanol and kerosene. The results of X-ray diffraction show that the existing phases in the synthesized powder are affected by the type of dielectric liquid, and different chemical compositions of the dielectric liquids lead to diverse chemical content in the produced debris. The average size of the particles produced in deionized water is the smallest, whereas substructure of the particles generated in kerosene has the smallest mean value. Debris synthesized by this method is nanostructured and can be readily converted to nanoscale WC-Co powder via heat treatment. Overall, the results show that, considering the production rate and particle size, deionized water is the best dielectric medium for nanocrystalline WC-Co precursor powder synthesis using EDM.