Research progress on binderless PCD and PCBN materials

The preparation method,sintering mechanisms,methods for improving their sintering behavior,and their properties for binderless polycrystalline cubic boron nitride(PCBN)and polycrystalline diamond(PCD)materials have been summarized and discussed.The dense binderless PCD and PCBN materials can be successfully sintered at the pressure and temperature of above 7 GPa and 1800℃,but the high-pressure & high-temperature(HPHT)sintering condition and mechanisms of PCD and PCBN will be strongly affected by the different start powers and micro catalyst or dopant.The physical vapor deposition(PVD)and chemical vapor deposition(CVD)are promising methods for preparing binderless PCD material because of the severe sintering condition for HPHT method,but many technical problems must be solved while using PVD and CVD to prepare binderless PCBN material.The binderless PCD and PCBN materials have excellent high temperature properties,especially that the properties of PCD and PCBN with nano-size grains or substructures are higher than those of single crystal.