MgO--Y/sub 2/O/sub 3/-stabilized ZrO/sub 2/ ceramics in exhaust gas sensor
The ZrO/sub 2/ electrolyte exhaust gas sensor was developed as the feedback signal device for control of engine air : fuel ratio at the stoichiometric ratio. The exhaust gas sensor electrolyte is ZrO/sub 2/, typically stabilized with CaO or Y/sub 2/O/sub 3/. Because of various operating advantages, the Y/sub 2/O/sub 3/-ZrO/sub 2/ ceramic is preferred; however, its cost is significantly greater than the CaO body. Data are presented on a series of MgO-Y/sub 2/O/sub 3/-stabilized zirconias that can be used in place of the Y/sub 2/O/sub 3/ fully stabilized material. The sintered MgO-Y/sub 2/O/sub 3/-ZrO/sub 2/ ceramic was fully stabilized and remained so after extended exposure in an engine durability test. The ceramic displayed some segregation of MgO throughout the matrix and a resistivity at typical exhaust temperatures (approximately equal to 600/sup 0/C) four to nine times higher than that of the MgO-Y/sub 2/O/sub 3/-ZrO/sub 2/ compositions. However, the ternary compositions appeared to be less expensive, reliable substitutes for the standard 8 mol percent Y/sub 2/O/sub 3/-ZrO/sub 2/ ceramic in the exhaust sensor application.
- Research Organization:
- General Motors Corp., Warren, MI
- OSTI ID:
- 7212200
- Journal Information:
- Am. Ceram. Soc. Bull.; (United States), Journal Name: Am. Ceram. Soc. Bull.; (United States) Vol. 56:5; ISSN ACSBA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROLYTES
EXHAUST RECIRCULATION SYSTEMS
EXHAUST SYSTEMS
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLLUTION CONTROL EQUIPMENT
STABILITY
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES