PRODUCTION OF ULTRA-FINE CERAMIC POWDER BY UTLIZING HIGH-FREQUENCY PLASMA

摘要

PURPOSE:To produce the title high-purity ultra-fine powder with high productivity by allowing a base gas consisting of =50vol% diatomic molecule or polyatomic molecule to react with the gas of a metal or a metal halide while stably generating plasma. CONSTITUTION:The grid current of the oscillating tube of a plasma generator is detected, the deviation between the detected quantity and a set value is obtained, impedance matching is carried out between a high-frequency power source and a high-frequency coil by changing the impedance of a turning circuit in accordance with the deviation, and the grid current is controlled to a fixed value to stably maintain the plasma. In the embodiment of the synthesis of AlN, the base gas (N2+Ar) 52 is sent from a gas inlet A to generate plasma 43 by a work coil 44, then a solid material (AlCl3) 51 is sublimed, transported to the position of the work coil, made into plasma, and allowed to react with N2, and AlN is synthesized. High-purity nitride, oxide, carbide, silicide, and boride can be obtained by this method.