| 摘要 |
PROBLEM TO BE SOLVED: To prevent such a problem in the conventional ceramic heaters as that when a conventional ceramic heater is used under a high temperature like a heater for heating an oxygen sensor of an automobile, cautions of alkali metals, alkaline-earth metals and the like added as sintering auxiliary or contained in alumina as impurities migrate from the anode side to the cathode side, causing ion migration, and the durability of the ceramic heater is deteriorated. SOLUTION: Ceramics constituting the substrate of this ceramic heater contains 90-99 weight % of Al2O3, 0.5-4 weight % of SiO2 and 0.5-6 weight % of oxides of rare-earth elements. The total amount of these materials constitutes 100 parts by weight, and the total amount of further contained MgO and CaO constitutes 0.4 parts by weight or less. |
