Abstract:
To solve the problem of adhesive phase wear for the traditional cemented carbide tools in the high-speed cutting process, the WC/Cr
3C
2/La
2O
3 tool materials were prepared by spark plasma sintering (SPS). The effects of Cr
3C
2 addition amount (mass fraction, 0%~2.00%) and process parameters (sintering temperature
1500~
1700 ℃ and sintering pressure 15~45 MPa) on the microstructure and mechanical properties of the tool materials were studied. The results show that, the optimum Cr
3C
2 content is 0.50%, and the WC/Cr
3C
2/La
2O
3 cemented carbide sintered at
1550 ℃ and 25 MPa has the best comprehensive properties as the relative density, bending strength, and Vickers hardness are 97.5%,
1281.0 MPa, and HV
2124.3, respectively. With the increase of sintering temperature, the relative density increases and the microstructure becomes more even for the WC-based tool materials. However, too high temperature leads to the abnormal growth of grains, the uneven distribution of microstructure, more porosity, and the lower mechanical properties. As the sintering pressure increases, the grain size reduces, the microstructure becomes more even, and the mechanical properties increase. While the sintering pressure is above 25 MPa, the mechanical properties of tool materials decrease.