PURPOSE: To prevent a carbon particle from being scattered due to heat and to obtain a highly pure sintered object that cannot be contaminated by the carbon particle even if the number of continuous hot hydrostatic pressurizations is increased by coating a part that is created by the carbon of a hot hydrostatic pressurizing device with a heat-resistant covering material.
CONSTITUTION: Since a support stand 4 including an upper support part 5 of a hot hydrostatic pressurizing device, a base heater 7, a side heater 8, and a container 6 are made of carbon, that part is coated with a boron nitride film. Although Si3N4 that is a material to be pressurized was subjected to hot hydrostatic pressurizing treatment under the pressurization conditions of a temperature of 1800°C and a pressurization force of 2,000 kgf/cm2 by N2 gas using the device, no carbon was adhered to the surface of Si3N4. Also, hot hydrostatic pressurization treatment was made at least for 10 times continuously without cleaning an insulator.
ICHINOSEKI KYOICHI
HORI SHIGEYUKI
TAMURA MASAYUKI
HIRAO TOSHIYUKI
