| 摘要 |
PURPOSE:To widen a usable range of the ceramic material without lowering the density by leaking heat generated on the contact face of the ceramic material with a part made of a metal by increasing heat conductivity, by adopting an amount of a sintering auxiliary added in a specific amount and specific sintering temperature conditions. CONSTITUTION:2-10wt.% One or more kinds of element oxides selected from Al2O3, Y2O3, Yb2O3, La2O3, Nd2O3 and Ce2O3 as a sintering auxiliary are added to a ceramic raw material consisting essentially of Si3N4 and the mixture is sintered at a temperature higher by 0-150 deg.C than the temperature at which the maximum density of the sintered compact is attained, For example, 100g of ethanol, 100g of silicon nitride (oxygen content: 1.5-2.0%) having 1mum particle diameter (specific surface area: 7cm<2>/g) and at least one sintering auxiliary among Y2O3, Yb2O3, etc., are charged in a 500L pot of a ball mill and 100g balls (diameter: 15mm) of silicon nitride for stirring are charged thereinto and these components are mixed at 300rpm for 60hr and dried by an evaporator until the mixture becomes powdery and the powder is granulated through a sieve having 0.5mm mesh and molded with a metal mold press, and then, the molding is baked at 1600-2000 deg.C in an N2 atmosphere. |
