Microstructure, mechanical, electrochemical and tribological performances of WC-based cemented carbides with different NbC amounts

WC-based cemented carbides with different NbC amounts (0, 1, 2, 3, 4, and 5 wt%) were prepared by the liquid phase sintering method. When the NbC amount was low, it was uniformly distributed in the cemented carbide and reduced the grain size of WC grains. With the increase of NbC amount, the inhibitory effect of WC grain was weakened, and the (Nb, W)C solid solution was gradually formed. The hardness and impedance modulus (| Z|0.01Hz) of the cemented carbide increased to 1546 f 7 kg/mm2 and 2200 f 31 Omega cm2 at 2 wt% NbC. In addition, for additions of 2 wt% NbC, the corrosion current density (icorr) was 4.849 f 0.5 x 10-6 A/cm2, the coefficient of friction (COF), 0.287 f 0.004 and the lowest wear rate of 0.85 f 0.03 x 10-5 mm3/(N & sdot;m) was observed. Therefore, the WC-based cemented carbides with 2 wt% NbC additive had the best comprehensive properties.