Synthesis of cubic boron nitride from rhombohedral form under high static pressure

Synthesis of cubic boron nitride from amorphous boron nitride containing oxide impurity using Mg–Al alloy catalyst solvent

“…It is well known that under the application of high pressures and temperatures the hexagonal modification of boron nitride (hBN) transforms into the cubic (cBN) and wurtzitic modifications (wBN) either directly or by the nucleation and growth process from a particular flux which is generated during the synthesis by the reaction of hexagonal boron nitride with the nitrides of alkali metals or alkaline earth metals. In recent years, efforts have been by a number of researchers to synthesize cBN from low ordered boron nitrides namely turbostratic boron nitride (tBN), amorphous boron nitride (aBN) and also from rhombohedral boron nitride (rBN) as the starting materials [1][2][3][4][5][6][7][8][9]. It has been found that hexagonal and amorphous boron nitride powders normally contain oxide impurity (B 2 O 3 ) with different concentration depending upon its method of preparation.…”

Cubic boron nitride—Ti/TiN composites: hardness and phase equilibrium as function of temperature

“…This material is similar to diamond, it is thermodynamically stable under high temperature and pressure [1][2][3][4][5]. Owing to their unique physico-mechanical properties cBN-based composites are frequently used in machine engineering as cutting blades useful especially for processing quenched steel and cast iron.…”

Growth of GaBN ternary solutions by organometallic vapor phase epitaxy

“…It is too far removed from the known reflections of graphitic or rhombohedral BN (both at about 28 ~ for Cu K s radiation (see Refs. [17][18][19] to be accounted for by some incorporation of Ga in BN. A peak in x-ray diffraction pattern similar to our peak at 20.6 ~ was detected when turbostratic BN was subjected to shock compression.…”