Improving wear resistance of cBN-based cutting tools using TiN coating on cBN powder surface

Abstract

TiN-coated cBN was successfully synthesized using the liquid phase deposition method with TiF4 as the Ti source. The crystal phase of the TiOx coating layer was transformed into Ti4O7 and TiN via sintering under a reduction atmosphere in a vacuum furnace. It was then completely converted to the TiN phase at a sintering temperature of 1200 °C. The coating layers exhibited a uniform thickness of approximately 20–40 nm, regardless of the sintering temperature. PcBN cutting tools prepared using the cBN@TiN powders showed excellent wear resistance under heavy cutting conditions; delivering an average machining distance of 10,766 m and a flank wear width of 0.3 mm in 108 min. This wear resistance is approximately four times that of a cutting tool manufactured using cBN powder.