Hardness and thermal stability enhancement of polycrystalline diamond compact through additive hexagonal boron nitride

摘要

Hexagonal boron nitride (hBN) was used as the additive in improving the hardness and thermal stability of poly-crystalline diamond compact under high temperature and high pressure. Indentation testing on diamond/cubic boron nitride (cBN) composites indicated a Vickers hardness of 96 +/- 7 GPa, rivaling the hardness of monocrystal diamond. Thermal gravimetric analysis (TGA) suggested that the composites of diamond/cBN are thermally stable in air up to similar to 910 degrees C which is higher than that of pure polycrystalline diamond compact (similar to 750 degrees C). Raman, TGA, x-ray photoelectron spectroscopic and microstructure analyses all revealed the features of diamond/cBN composition beyond both diamond and cBN. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.