【作者】 沈杰；

【导师】 简家文；

【作者基本信息】 宁波大学 ， 通信与信息系统， 2009， 硕士

【摘要】 固体电解质氧传感器一直以来在汽车领域有着重要的应用,而片式极限电流型氧传感器以其测试精度高、响应速度快、使用寿命长以及使用过程中不需基准气体等特点受到广泛重视,可作为氧仪表的核心元件。本文在国内外研究基础上围绕小孔型极限电流氧传感器的开发和研究,根据氧传感器的相关制备工艺,对固体电解质材质、多层结构设计、多层叠成热压、烧结工艺和信号检测等方面进行了细致的研究。选用8mol%Y₂O₃稳定ZrO₂（YSZ）（以下简称8YSZ）流延片和5mol%Y₂O₃稳定ZrO₂（YSZ） （以下简称8YSZ）流延片进行了常规烧结;对烧结后YSZ进行了收缩率、热膨胀和交流阻抗谱测试与分析;分别计算了550℃温度以下5YSZ和8YSZ的晶粒电阻、晶粒电容、晶界电阻和晶界电容;通过Arrhenius曲线拟合得到了晶界活化能和晶粒活化能。采用5YSZ流延生瓷片,完成了对传感器多层结构分布的设计,经过厚膜丝网印刷、叠片热压和多层共烧制备了氧化锆极限电流型氧传感器;通过数字显微镜、扫描电子显微镜（SEM）等手段对其进行了物理性能的表征,并对该传感器在923K温度下氧浓度1100ppm～90%范围内的气敏特性、高低气压影响和响应时间等进行了输出特性的研究,并测试分析了电解质工作温度对极限电流的影响;同时结合不同实际应用设计了两套氧传感器的测试系统。实验结果表明共烧制备的传感器在上述氧浓度范围内具有较好的电流平台,且极限电流与氧浓度存在正常扩散模型具有的线性关系;工作温度在923K,氧浓度在21.24%和5.06%之间变化对应的传感器响应时间呈现出较好的重复性,且均在1秒以内,基本满足氧浓度检测的应用要求。更多还原

【Abstract】 Solid electrolyte oxygen sensor has been popularly used in automotive industry and planar limiting-current oxygen sensor is valued for its characters of high precision, quick response, durability and no reference air, which make up the core component of oxygen device. According to the relevant research at home and abroad, the oxygen sensor was studied from the aspects of Solid electrolyte material, structural design, screen printing, stacking hot pressing and sintering process. Further more, the signals of sensor were detected in detail.In the experiment, 5mol% yttrium stabilized zirconia ceramics and 8mol% yttrium stabilized zirconia ceramics, which had been sintered, were investigated by shrinkage rate, thermal expansion instrument, digital microscope and AC impedance. Furtherly the resistance of Grain boundary and resistance of Grain were calculated by the AC impedance spectroscopy below 550℃. Meanwhile, activation energy of grain and Grain boundary were gained in the fitting curve of Arrhenius.A thin-film limiting-current type oxygen sensor using 5mol% yttrium stabilized zirconia (5YSZ) was developed successfully through the technology of tape casting. It was made from tape-casting layers by screen printing, stacking hot pressing and multilayered cofiring process. Meanwhile the physical characteristics were investigated by SEM and digital microscope. The response time and I-V curve of oxygen sensor sample were tested at 923K in a mixture of the N2-O2 with the oxygen concentration between 1100ppm and 90%. Further more, the influence of the ambient pressure and the temperature of solid electrolyte were also developed. Finally, two test systems of oxygen sensors were introduced with their different applications in detection. The result distinctly shows that stable current platforms of the sensor prepared by multilayered cofiring are formed in the scope of the oxygen concentration mentioned previously, and a good linear relationship between the limiting current and oxygen concentration is illustrated according to Normal diffusion model; Simultaneously it is indicated that the sensor has good repeatability at 923K with the oxygen concentration varying from 5.06% to 21.24% and the response time is within 1 second,which is able to meet the need of basic application in oxygen detection.更多还原