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Combustion Synthesis of Boron Nitride via Magnesium Reduction Under Low Nitrogen Pressures
Author(s) -
Chung ShyanLung,
Hsu YuHsiang
Publication year - 2014
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.13154
Subject(s) - combustion , boron nitride , magnesium , yield (engineering) , nitrogen , boron , materials science , nitride , chemical engineering , chemistry , metallurgy , inorganic chemistry , organic chemistry , nanotechnology , layer (electronics) , engineering
A combustion synthesis process was developed for the synthesis of h‐ BN powder. B 2 O 3 , Mg , NH 4 Cl , and NaN 3 were used as the reactants and they were mixed and pressed into a reactant compact, which was then wrapped up with an igniting agent (i.e., a mixed powder of Mg and Fe 2 O 3 ). With the presence of NH 4 Cl and NaN 3 in the reactant compact and the wrapping of the igniting agent, the combustion synthesis reaction could be carried out under low N 2 pressures (<1.0 MPa) with high product yields (up to 79%) and high specific surface areas (SSA) of the product powder (up to 151 m 2 /g). Effects of process parameters on the product yield, SSA, and combustion temperature were investigated and a reaction mechanism was proposed to explain the effects. The synthesized h‐ BN was platelike crystals and their SSA was found to increase with decreasing maximum combustion temperature under most of the experimental conditions. This is explained by the growth time of the crystals, which is considered to be shorter under the condition with a lower maximum combustion temperature.