Study on fabrication and tribological properties of TiB₂-based cutting tools

Three groups of TiB₂-based cutting tools with different compositions were prepared by hot pressing sintering. The microstructure, mechanical properties and tribological properties of B73H18N0, B49H18N24 and B41H18C32 samples were compared and analyzed. The results show that no new phase is formed in B49H18N24 and B41H18C32 samples which have TiN and TiC added. The hardness, bending strength and fracture toughness of three TiB₂-based cutting tools samples are respectively B73H18N0 > B41H18C32 > B49H18N24, B73H18N0 > B41H18C32 > B49H18N24 and B41H18C32 > B49H18N24 > B73H18N0. Under the same sliding speed or load, the wear rate of three TiB₂-based cutting tools against TA2 titanium alloy increases with the increase of load or sliding speed, and the wear rate of B41H18C32 sample is the lowest, indicating that B41H18C32 sample has relatively better wear resistance when grinding TA2 titanium alloy. The wear mechanisms of three TiB₂-based cutting tool specimens during dry friction and wear are abrasive wear, adhesive wear and oxidation wear, and mainly adhesive wear.