Effect of Shock Sintering Temperature and Carbon Content of the WC–Co Hardmetal Anode on the Mass Transfer in Electrospark Deposition

The paper examines how the shock sintering temperature and carbon content of the VK25 hardmetal and the process time and discharge energy in the electrospark deposition of the hardmetal onto steel 45 samples influence the mass transfer, thickness, and microhardness of the resultant surface layers. The experiments were performed employing an Elitron-24 unit providing a discharge energy of 0.34–1.1 J. The VK25 hardmetal was produced by shock sintering in the range 1150–1300°C using WC with different carbon contents. For the maximum mass transfer, the hardmetal sintering temperature should be 100–150°C lower than the temperature at which samples with the highest strength were produced. The maximum mass transfer was observed when the hardmetal was depleted of carbon (3.9 instead of estimated 4.59 wt.%). A protective layer 100–200 μm thick, with a hardness of 8.0–13.7 GPa, was produced on the steel samples.