Vacuum tribological properties and impact toughness of polycrystalline diamond based on titanium-coated diamond particle

In this work, the diamond particles were deposited with titanium (Ti) by the magnetron sputtering, and the polycrystalline diamond compact synthesized by the Ti-coated diamond particles (Ti-PDC) was prepared by high temperature and high pressure (HTHP) sintering method. The scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) results show that the Ti coating uniformly distributes on the surface of diamond particles. The results of X-ray diffraction (XRD) indicate that the TiC phase has been produced during the sintering process. The impact toughness of the Ti-PDC is higher than that of the pristine polycrystalline diamond compact (P-PDC). In addition, the friction coefficients of Ti-PDC under different vacuum conditions reveal lower values than those of the P-PDC. A less number of exfoliated pits can be observed on the worn Ti-PDC surface. The improved impact toughness and vacuum friction performance of Ti-PDC may be attributed to the enhanced bonding strength between diamond particles, which is induced by the TiC phase. In brief, the Ti -coated diamond particles can improve the bonding strength between diamond grains and thus yield to an enhanced service performance of the PDC.