Effect of Sintering Temperature on the Microstructure and Mechanical Properties of Nanocrystalline Cemented Carbide

WC-Co nanocrystalline nitrogen-containing cemented carbides were prepared by vacuum sintering and low pressure sintering. The sintering processes of Cr₂(C,N) doped nano WC-Co powders were studied by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of sintering temperature on the microstructure and mechanical properties of nanocrystalline cemented carbide was studied by scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM) and mechanical property test. The results showed that the nano WC grains began to grow in the solid phase sintering stage. A high-performance nano-nitrogen-containing cemented carbide with uniform microstructure and good interfacial bonding can be obtained by increasing the sintering temperature to 1 380 °C. It has a transverse rupture strength (TRS) of 5 057 MPa and a hardness of 1 956 HV30.