Polycrystalline cubic boron nitride, CBN, is a material with excellent hot hardness that can be used at very high cutting speeds. It also exhibits good toughness and thermal shock resistance.
Modern CBN grades are ceramic composites with a CBN content of 40-65%. The ceramic binder adds wear resistance to the CBN, which is otherwise prone to chemical wear. Another group of grades are the high content CBN grades, with 85% to almost 100% CBN. These grades may have a metallic binder to improve their toughness.
CBN is brazed onto a cemented carbide carrier to form an insert. The Safe-Lok™ technology further enhances the bondage of CBN cutting tips on negative inserts.
Applications
CBN grades are largely used for finish turning of hardened steels, with a hardness over 45 HRc. Above 55 HRc, CBN is the only cutting tool which can replace traditionally used grinding methods. Softer steels, below 45 HRc, contain a higher amount of ferrite, which has a negative effect on the wear resistance of CBN.
CBN can also be used for high speed roughing of grey cast irons in both turning and milling operations.
CB7015 PVD coated CBN grade with ceramic binder for continuous turning, and light interrupted cuts in hardened steels.
CB7025 CBN grade with ceramic binder for interrupted cuts and high toughness demands when turning hardened steels.
CB7050 High content CBN grade with metallic binder for heavy interrupted cuts in hardened steels and for finishing grey cast iron. PVD coated.