| 摘要 |
PURPOSE:To obtain nitride ceramics, containing reduced grain boundary phase components and improved in characteristics, by forming a mixture of a nitride ceramic raw material powder with sintering assistant powder, sintering the formed compact and heat-treating the resultant sintered compact in a gas atmosphere containing a substance opposite to the grain boundary phase components of the above-mentioned sintered compact. CONSTITUTION:Nitride ceramics, e.g., AlN, is produced by the following procedures. That is CaCO3 as a sintering assistant is added to AlN powder and homogeneously mixed in ethanol. Stearic acid as a binder is then added to the above-mentioned mixed powder and pressurized to prepare a disklike compact. The afore-mentioned compact is subsequently heated in a graphite crucible at 500 deg.C to remove the binder. The resultant compact is then sintered in N2 atmosphere. The obtained compact is subsequently heat-treated in a component opposing grain boundary phase substances of the above-mentioned compact, e.g., CF4 gas atmosphere, at a sufficiently higher temperature (e.g., 1600 deg.C) than ordinary temperature to provide nitride ceramic, i.e., AlN. The resultant AlN has high thermal conductivity and excellent in bending strength. |
