Investigation of the Structural Features of Boron Nitride after Mechanical Activation in Attritor and Planetary Mill Followed by Agglomeration at High Pressure and Temperature
V. T. SENYUT1, S. A. KOVALEVA1, T. V. GAMZELEVA2, T. F. GRIGORIEVA3
1Joint Institute of Mechanical Engineering, National Academy of Sciences of Belarus, Ul. Akademicheskaya 12, Minsk 220072 (Belarus)
2Powder Metallurgy Institute, National Academy of Sciences of Belarus, Ul. Platonova 41, Minsk 220005 (Belarus)
3Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch of the Russian Academy of Sciences, Ul. Kutateladze 18, Novosibirsk 630128 (Russia)
Keywords: гексагональный нитрид бора, механоактивация, аттритор, планетарная шаровая мельница, удельная поверхность, химическая очистка, hexagonal boron nitride, mechanical activation, attritor, planetary ball mill, specific surface, chemical purification
Abstract
Effect of mechanical activation (MA) of hexagonal boron nitride ( h BN) powder with different intensities in attritor and in a planetary ball mill (PBM) on the structure and phase composition of materials based on this compound was studied. Mechanical activation of h BN powder was carried out in order to decrease the parameters of synthesis of cubic boron nitride ( c BN) due to the formation of nanostructure in h BN. The stoichiometry of h BN is observed to decrease during MA due to partial decomposition. Mechanical treatment of h BN powders in PBM proceeds more intensively and leads to the formation of particles with crystallite size 5-10 times smaller than the size of crystallites formed during treatment in attritor. The specific surface increases by a factor of 3-6. After agglomeration of powders after MA at a pressure above 7 GPa, the phase composition of the resulting material is independent of the intensity of MA and is characterized by the presence of the cubic phase of BN alone.
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