The effect of binder component and oxygen partial pressure on the high-temperature oxidation behaviors of WC cemented carbides

The oxidation of the WC cemented carbides result in the formation of oxide phases, pores and cracks, ultimately reducing the performance and lifespan of the cemented carbide. Therefore, it is essential to study the oxidation behavior and mechanism of cemented carbide to improve its oxidation resistance and prolong its lifespan. The oxidation rate of cemented carbides is significantly affected by the components of the binder and oxygen partial pressures. When Ni and Zr are used as binders in preparing WC cemented carbides, improved oxidation resistance is attained because of the formation of a dense oxide layer on the cemented carbide surface under high oxygen partial pressures. When using 5% Ni & 15% Zr as the WC binder and oxidizing at 800 °C for 1 h, the oxidation rate reaches its peak at an oxygen partial pressure of 0.21, with an oxide layer thickness of 721 μm. Beyond this point, the oxidation rate decreases as the oxygen partial pressure increases. In contrast, using Fe and Zr as binders leads to an increase in surface flaws as the oxygen partial pressure increases. When using 10% Fe & 5% Zr as the WC binder and oxidizing at 800 °C for 1 h, the oxidation rate rises with increasing oxygen partial pressure, although the rate of increase progressively diminishes. Therefore, adjusting the binder components is an effective method for enhancing the oxidation resistance of WC cemented carbides.