Cubic nitride cutting tool insert with excellent resistance to notches and blade breakage

摘要

A cutting tool insert which can, for example, be used for machining of hardened steel, hot and cold working tool steel, die steel, case hardened steel, high speed steel and ductile grey cast iron and composed of a composite comprising a cBN-phase and a binder phase comprising a titaniumcarbonitride phase and a TiB 2 phase is disclosed. In the XRD pattern from the composite using CuKa-radiation, the peak height ratio of the strongest (101) TiB 2 peak and the strongest cBN (111) peak is less than 0.06, the (220) peak from the titanium carbonitride phase in the XRD-pattern intersects both vertical lines of the PDF-lines of TiC (PDF 32-1383) and TiN (PDF 38-1420) and the lowest intersected point height is at least 0.15 of the maximum (220) peak height of the ceramic binder phase. The insert is made by powder metallurgical methods milling, pressing and sintering, the sintering being performed at lowest possible temperature for shortest possible time necessary to obtain a dense structure.