PURPOSE: To improve durability, by making the blocking end heavier than the opening side of a solid electrolyte as the thickness of a heat-resistant metallic oxide to be formed on an electrode on the exhaust gas side, and also by providing it with a prescribed porous structure at the same time.
CONSTITUTION: Porous Pt electrode layers 2a and 2b are provided by thermal decomposition process on the inside and outside circumferential surfaces of an oxygen ion conductive solid electrolyte 1 composed of a stable zirconia sintered body to which 5W10mol% of Y2O3 is added. Onto the electrode layer 2a, which is on the exhaust gas side, of the Pt electrode layers, MgO-Al2O3 spinel powder is applied by plasma flame coating process to form a coating 3. The coating 3 is to be of such a structure that thickness becomes gradually heavier toward the blocking end from the opening side of the solid electrolyte 1, porosity of Region A is appropriate (0.5W 1%) so that very little gas passes in the region A stretching from the center to the foot section of the solid electrolyte 1, and porosity of Region B stretching from the center to the blocking end is approximately 5% with a number of fine pores allowing the gas to pass through.
YAMAKAWA KUNIO
OKINAKA HIDEYUKI
| JPS54116290A | 1979-09-10 | |||
| JPS5497490A | 1979-08-01 |