PCBN cutting tools in a competitive market

The consumption of polycrystalline cubic boron nitride (PcBN) is - despite the comparatively high price and restrictions in tool geometry - continuously growing. The development is supported by the increasing acceptance of high-speed, high-performance and hard and/or dry machining. Meanwhile several compositions of cubic boron nitride are available comprising materials with different binder compositions, binder volume fractions, and grain sizes of the cBN-phase. In this way the matching of properties of PcBN tools to the requirements and the performance of the tools is improved. The paper describes the latest developments and compares the properties and applications of different PcBN compositions with competing materials like cemented carbides and ceramics. The properties considered are hardness, strength, fracture toughness, hot hardness and thermal conductivity. Several applications are discussed with respect to the mechanical properties. Furthermore, several peculiarities which may occur in the use of PcBN tools are presented and discussed.