Incongruent reduction of tungsten carbide by a zirconium-copper melt

The reduction of tungsten carbide (WC) to elemental tungsten by reaction with a Zr–Cu melt was examined. Dense WC disks were immersed in a vertical orientation in molten Zr₂Cu at 1150–1400 °C for 1.5–24 h. Continuous, adherent layers of W and ZrC formed at WC/melt interfaces. The rates of thickening of the W and ZrC product layers were examined as a function of reaction time and temperature and position along the vertical WC surface. Such kinetic data, along with microstructural analyses, indicate that the incongruent reduction of tungsten carbide is likely to be controlled by carbon diffusion through one or both of the product layers.