The influence of pH on thermal fatigue crack propagation behavior of WC–8Co cemented carbide

Abstract The notch quench method was used to study the influence of pH values on thermal fatigue crack propagation behavior of WC–8Co cemented carbide. The pH values of the aqueous solutions were varied between 5.2, 7.4 and 8.8. The results show that the corrosive environment has a strong influence on the thermal fatigue crack propagation behavior of the materials for testing. Acidic and alkali environment can reduce the thermal fatigue crack initial life and increase the crack propagation rate. Thermal attack results in a significant loss of hardness and the effect is even visible in an acidic environment. In all cases, only WO 3 and CoWO 4 phases are present in the oxides. The mode of crack propagation requires the simultaneous actions of thermal attack and corrosion.