Production of the Planar Exhaust Gas Oxygen Sensor
|School||Huazhong University of Science and Technology|
|Keywords||planar automotive exhaust gas sensor YSZ multilayer ceramic lamination thermal shock resistanc|
Planar automotive exhaust gas sensors widely applied in the three-way catalyst system are used to detect oxygen in exhaust gas and control the air/fuel ratio to stay at the stoichiometric point which is 14.7 to make ture the engines work at the best condition. Because of the stricter vehicle emission control laws day by day, the worldwide market will be remarkably extended.In this paper, the fabrication technique for planar exhaust gas sensors has been explored. In order to fabricate exhaust gas sensors with better performance, we investigated and optimized the following techniques:Materials for experiments are researched. The particle size and its distribution were measured with a Laser Particle Size (LPS) analyzer. The surface morphology and microstructure of powders were examined with Scanning Electron Microscope(SEM). Desirable phases were identified with X-ray diffractioner.Tape casting, screen-printing and lamination processes, simple and cost-effective techniques, were used to fabricate the exhaust gas sensors. Support was prepared by tape casting. Functional thin films were prepared by screen-printing. Final assembly was prepared by lamination. Several experiments were conducted to optimize the processing parameters of tape casting, screen-printing and lamination. The influence of the parameters on the quality of production process was discussed.The support/functional films multilayer ceramic green bodies sintering processes were researched. Factors resulting in shrinking were analyzed and discussed and the two-stage sintering process was explored and optimized.The novel insulation materials with better sintering performance was investigated. The thermal shock behavior of exhaust gas sensors was researched, the methods of improvement the thermal shock resistance of exhaust gas sensors were put forward. The feasibility of novel metal which could instead of platinμm used in the heating electrode was reseached, the long time reliability of the novel heating electrode was checked.The responses of the samples of final produtions were mearsured in a engine emission atmosphere, and the electrical output signal was analyzed. After all these checking, the exhaust gas sensors productioned by ourself are believed as good value production.