Microstructure and Mechanical Properties of Functionally Graded Cemented Carbides of Coarse Grain Prepared by Solid Carburizing

The cemented carbide with coarse grain is widely used in mining drilling due to high thermal conductivity, high strength and impact resistance and so on. Functionally graded cemented carbide with coarse grain were prepared by solid carburizing in this research. The different carburizing process was studied, and the relationship between carburizing process and the microstructure, mechanical properties were studied. The carburizing efficiency was lower and the formation the gradient layer was slowly for coarse grain cemented carbide at different carburizing temperatures. When the carburizing temperature was lower than 1440 °C, it was difficult to prepare the functional gradient cemented carbide. While higher than 1450 °C, functional gradient cemented carbide can be formed by solid carburizing. The thickness of gradient layer was close among carburizing temperature from 1450 °C to 1490 °C. However, the carburizing time had the more significant effect on the carburizing reaction the formation of the gradient layer.