Effect of transition metal carbides on mechanical properties of polycrystalline diamond by HPHT sintering.

In this study, W-MeC-Si/PCD (Me = Ti, Zr, Hf, V, Nb and Ta) composite materials were prepared via high pressure and high temperature (HPHT, 5.5 GPa and 1600 °C) sintering, the effect of the addition of transition metal carbides on the micromorphology, phase composition and mechanical properties of PCD has been systematically studied, and various mechanical data of W-TaC-Si/PCD have been provided. The results show that the addition of MeC is conducive to the improvement of the mechanical properties of PCD. The sample with TaC has the best mechanical properties, and its flexural strength, relative density, hardness and fracture toughness reached 743.5 MPa, 99.75%, 63.4 GPa and 8.1 MPa m1/2, respectively. Finally, the toughening mechanism of W-MeC-Si/PCD is also discussed. The improvement of fracture toughness can be attributed to the change of fracture mode and the pinning effect of MeC dispersion in the binder. [ABSTRACT FROM AUTHOR]