The influence of Li-based catalysts/additives on cBN crystal morphologies synthesized under HPHT

In this paper, various cubic boron nitride (cBN) crystal morphologies were synthesized using hexagonal boron nitride (hBN) as raw materials and Li3N, LiH, and LiNH2 as catalysts/additives under high pressure and high temperature (HPHT).These crystal shapes contain thick-plate, spherical, octahedral or hex-octahedral, flat cone and flaky hexagonal morphologies. The reasons of various crystal shapes synthesized can be summarized as follows: various catalysts/additives take on distinct properties under HPHT, which have crucial effects on the cBN crystal morphologies synthesized. Catalyst Li3N tends to grow cBN with thick-plate morphology, catalyst LiH would induce the growth of cBN tending to integrated octahedral morphology, and catalyst LiNH2 would play diverse roles for cBN crystal morphologies in various systems.

Research Highlights
► The various morphologies cBN monocrystals have been successfully synthesized.
► The special shape of cBN crystal can be provided by different Li-based catalysts/additives.