Interfacial structure and performance analysis of PcBN composites with metal/ceramic binder

To investigate the effect of binder type on the interface and properties of PcBN composite, a series of PcBN composites with Al, TiN, Co, Ni, and W as binders were prepared under the conditions of 5.5–6 GPa, 1450–1550 °C, and 50 min, the interfacial bonding mechanism and material properties of PcBN composite were analyzed and discussed using SEM/EDS, XRD, and mechanical testing equipment. The results show that new phases are generated in the sintering of PcBN composites with different types of binders, which are uniformly distributed at the grain boundaries or in the interstices of grains to form a dense organization; cBN-cBN and cBN-TiN grain boundaries are formed in metal and ceramic binder PcBN, respectively, and the microhardness reaches 41.66 GPa at the highest level. In addition, the metal binder mainly diffuses by capillary force, while the ceramic binder mainly infiltrates with each other. This shows that the mutual infiltration of the phases within the PcBN material layer and the cemented carbide layer is the key factor in improving the interfacial bond strength.