Assessment of the performance of TiB2 nanoparticles doped cBN-TiN-Al-Co composites by high temperature high pressure sintering

Abstract

In this study, cBN composites incorporating TiN–Al–Co were synthesized via high temperature and high pressure (HPHT) methods. TiB2 nanoparticles were employed to optimize cBN cutting tools capacity for precise cutting. The effects of TiB2 nanoparticles on the preparation and properties of cBN composites were comprehensively investigated. The results show that the presence of TiB2 nanoparticles uniformly distributed in the interface not only promotes the formation of AlCo but also inhibits crack propagation, which contributed to the enhanced mechanical properties. With the appropriate addition of TiB2 nanoparticles, cBN composites obtained the compact and fine microstructure and presented better mechanical properties. Consequently, cBN composites incorporating 6 wt% TiB2 nanoparticles exhibited excellent relative density of 99.81%, bending strength of 731 MPa, hardness of 49.5 GPa, fracture toughness of 7.4 MPa⋅m1/2, and abrasive ratio of 2.1. Such composites with outstanding mechanical properties might be promising for cutting tools.