| 摘要 |
PURPOSE:To produce a sintered material having low oxygen content and improved purity and quality by synthesizing ultrafine powder of AIN in a high-frequency thermal plasma reactor and forming the powder in the form of a green body in an atmosphere having extremely low oxygen content. CONSTITUTION:N2 gas is introduced into a reactor evacuated to a vacuum of about 0.1Torr, high-frequency thermal plasma 10 is generated in the reactor, Al powder 13 is introduced into the plasma to react the powder and produce ultrafine AIN powder 15 and the powder precipitated and deposited on the surface of a water-cooled rotary drum 16 is scraped off with a scraper 17 and collected in a collection vessel 31. A partition door 34 is opened through the operation port 33 of a chamber 32 for the addition of assistants and mixing with a mill. The ultrafine powder 15 is taken out of the reactor, weighed with a chemical balance 35, compounded with a sintering assistant 36 and a mixing assistant 37, mixed with each other on a milling and mixing vessel 40, transferred to a vacuum chamber 39 and dried in vacuum by opening the lid of the vessel 38. The obtained ultrafine powder 15 is transferred to a press-forming chamber 45, added with a forming assistant 46 and mixed in a mortar 47 to obtain powdery raw material 48 for the sintering of AlN. The powdery raw material 48 is inserted into a press mold 49, pressed with a simple hand-press 50 and the obtained green body 51 is inserted into a furnace core tube 52, calcined and sintered. |
