| 摘要 |
PROBLEM TO BE SOLVED: To obtain a silicon nitride ceramic having high heat conduction and to provide the method for producing it. SOLUTION: A slurry is prepared by adding a sintering assistant and a single crystal of β-silicon nitride as seed crystal to silicon nitride raw material powder and dispersing the obtained mixed powder in a dispersant. The slurry is subjected to a forming process such as sheet forming or extruding forming, and the obtained silicone nitride forming, whose single crystals of β-silicon nitride are oriented in a plane, is subjected to a degreasing treatment. Optionally, the degreased material is made dense by a hot press treatment, etc., and further sintered at 1,700-2,000 deg.C in a nitrogen atmosphere under 1-100atm to obtain the objective silicon nitride sintered body. The sintered body has a structure in which silicon nitride crystals are oriented in one direction and a heat conduction of 100-150W/mK in the direction of the crystal orientation. |
