Enhanced thermal and mechanical performance of polycrystalline diamond compact by introducing polycrystalline cubic boron nitride at the grain boundaries

Ti-coated diamond and cBN with TiCN as the binder were used to fabricate the TDBN-TiCN series PDC with improved heat resistance, wear resistance and impact toughness by a China-type cubic high-pressure apparatus (5.5?6.5 GPa, 1450?1650 ?C) for drilling. Under high temperature and high pressure conditions, the Co in the cemented carbide substrate penetrated into the PCD layer and the binder TiCN to form a metal-ceramic binder system. It can promote the formation of polycrystalline cubic boron nitride (PcBN) from cubic boron nitride particles at the grain boundaries, and promote the TDBN-TiCN series PDC to have the performance of PCD and PcBN. Compared with the TDBN series PDC developed by our former research, the wear resistance of TDBN-TiCN series PDC increased by 17% and the impact toughness increased by 26%. In the TDBN-TiCN series PDC, some heat resistant phases, such as PcBN, TiB2 and TiN, were formed so as to enhance the initial graphitization and oxidizing temperatures to 958 ?C, which was 8 ?C higher than the TDBN series PDC (950 ?C) and 178 ?C higher than conventional PDC (780 ?C).

Automated summary

The TDBN-TiCN series PDC, made with Ti-coated diamond and cBN with TiCN binder, exhibited improved heat resistance, wear resistance, and impact toughness. It formed a metal-ceramic binder system under high temperature and pressure conditions, enhancing the wear resistance and impact toughness. The formation of heat resistant phases in the TDBN-TiCN series PDC contributed to an increased initial graphitization and oxidizing temperature.