片式氧传感器电解质薄膜的制备及其性能研究
Fabrication and Properties of Electrolyte Film Used in Planar Oxygen Sensor
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摘要: 确定了钇掺杂稳定氧化锆超细粉料和有机添加剂组成的浆料的配比, 流延并烧结成了用于片式氧传感器的陶瓷薄膜。通过浆料粘度变化分析了分散剂的作用效果, 研究了粘结剂和增塑剂对成膜效果和素坯相对密度的影响;采用综合热分析仪等手段研究了浆料中有机添加剂的烧除温度和热失重变化, 并设计了合适的烧结制度;利用X射线衍射 (XRD) 及电子扫描显微镜 (SEM) 分析了最终烧结体的晶体结构和微观形貌;测量了抗热震及电性能。研究结果表明:素坯薄膜相对密度达55%, 素坯内颗粒分散均匀, 无硬团聚;采用相应的烧结制度在最佳烧结温度1450℃下得到了相对于理论密度达98%, 晶粒均匀, 晶界明显, 几乎没有气孔的致密化薄膜;其抗热震性能达45次以上, 电性能良好, 是用于片式氧传感器的理想薄膜材料。Abstract: The slurry made of yttria stabilized zirconia (YSZ) powders and organic additives was investigated.YSZ films used in oxygen sensors were obtained by tape casting.The influence of the dispersant on slurry was investigated by detecting the viscosity and the green relative density and film quality with the different binder and plasticizers were researched.The temperature of burnout of organic additives in the slurry of YSZ was analyzed by TG-DTA and a corresponding sintering program of the YSZ film was designed.X-ray diffraction (XRD) and scan electron microscope (SEM) were employed to observe the crystal structure and micrograph of sintered films.The performance of thermal shock resistance and conductivity were surveyed.The results showed that the green relative density achieves 55wt% and the YSZ film with almost no micro pores, but clearly grains and grain boundary and 98% of theoretical density can be gained at the final sintering temperature of 1450℃.Thermal shock resistance and conductivity are better than that of tube oxygen sensors indicating that the YSZ film is suited for electrolyte films used in oxygen sensors.