Method of manufacturing and AlN / BN composite sintered material of AlN / BN composite powder

摘要

PROBLEM TO BE SOLVED: To solve the problem that an AIN/BN composite sintered material produced by mixing conventional commercial BN and AIN powders with each other gives a sintered product having anisotropy ascribable to the orientability of platy BN crystals and therefore having anisotropy of thermal conductivity, which extremely lowers thermal conductivity in a uniaxial pressure direction.;SOLUTION: The method for producing the AIN/BN composite powder comprises mixing an AIN powder with a boron compound and an NH₂-containing compound to form a raw material powder and subjecting the raw material powder to low-temperature heating and subsequent reduction heating and high-temperature heating to nitride the boron in the boron compound. Thus, the AIN/BN composite powder containing 3 to 40 vol% BN and having a low oxygen content can be produced. By using the obtained AIN/BN composite powder as a sintering material, it is possible to uniformly disperse fine BN particles into the AIN matrix of the sintered compact and therefore to make an AIN/BN composite sintered material possessing both high strength and free machining properties without detriment to high thermal conductivity inherent in AIN by sintering at atmospheric pressure.;COPYRIGHT: (C)2005,JPO&NCIPI