CBN Composites with a Nanosized Binding Phase

摘要

In this work cBN-TiN composites were studied. The composites were prepared by the HPHT technique (p=8 GPa, T=1750°C). A TiN binding phase was used in two forms: as micro and nanomaterials. Thermodynamic calculations showed that formation of new phases in the cBN-TiN composites was not possible in the experimental conditions which was confirmed by XRD investigations carried out. The surface morphology of nanocomposites was studied by scanning electron microscopy. The structure of these composites was compact; a TiN phase was uniformly distributed between cBN grains. Hardness was measured by the Vickers method using an indentation load of 9.81 N. The hardness of the investigated samples was dependent on the volume and grain size of the binding phase. Young's modulus of elasticity was determined, but its value was found to be dependent on the grain size of the TiN phase.