Affiliation:
1. Guangxi Key Laboratory of Superhard Material; National Engineering Research Center for Special Mineral Material; Guangxi Technology Innovation Center for Special Mineral Material; China Nonferrous Metal (Guilin) Geology and Mining Co. Ltd., Guilin, PR China
Abstract
Polycrystalline cubic boron nitride (PcBN) cutting tool materials were
prepared by mixing cBN (85 wt.%) and TiN-Ti-Co (15 wt.%) micropowders under
high temperature and ultra-high pressure. X-ray diffraction and scanning
electron microscopy were employed to analyse the phase composition and
microstructure of the composites. The effects of sintering temperature on
the mechanical properties and cutting performance of the PcBN ceramics were
also investigated. The results indicated that at the ultra-high pressure of
6GPa and temperatures ranging from 1400 to 1700?C, the PcBN composites
consist of BN, TiN, TiB2 and Co phases. The PcBN sintered at 1700?C
exhibited the most favourable comprehensive mechanical properties, including
a flexural strength of 909MPa and microhardness of 36.8GPa. In addition, the
cutting tool fabricated from the PcBN composite sintered at 1700?C showed
superior cutting performances in testing with 40Cr mechanical parts.
Publisher
National Library of Serbia