Effect of Carbon Content and CeO2 Addition on Thermal Properties and Surface Morphology of Ultra-fine WC-9Ni-0.4Cr3C2 Cemented Carbide

Four groups of ultrafine WC-9Ni-0.4Cr(3)C(2) cemented carbide samples with different carbon and CeO2 content were prepared by a powder metallurgy method. The thermal properties of the alloys were analyzed using thermal constant HotDisk analyzer through transient plane heat source method (TPS) technology; meanwhile, the phase composition and surface morphology of the alloys after sintering were also studied by XRD, SEM and EDX. The results show that with the CeO2 content increasing, the thermal conductivity and the thermal diffusion coefficient of the alloy decrease, while the specific heat capacity changes slightly. When the carbon content in the WC-9Ni-0.4Cr(3)C(2)-CeO2 is low, Ce tends to gather in the alloys' surface in the form of sulfide and oxide. With the increasing of carbon content, the gathering phenomenon of Ce in the alloy's surface gradually disappears, and the thermal conductivity and thermal diffusion coefficient rise obviously. Meanwhile, carburization occurs in the alloys.