Han S.-H.,Chosun University |
Noh H.-S.,Gaustek Co. |
Na D.-M.,Gaustek Co. |
Jin G.-H.,Gaustek Co. |
And 2 more authors.
Journal of the Korean Ceramic Society | Year: 2011
In order to fabricate 8YSZ thick film by silk screen printing, YSZ(yttria-stabilized zirconia) commercial powder was used as starting materials. Paste for screen printing was made by mixing 8YSZ powder and organic vehicles. 8YSZ thick film was formed on Al2O3 substrate. The crystal structure, and microstructure were investigated. Grain size of 8YSZ was increased with increasing calcination temperature and rapid grain growth was shown after calcination at 1300oC. Microstructure showed the mixture of large and small grain size after 1400°C sintering. Shrinkage rate of 8YSZ thick film sintered at 1400°C was more than 40%.
Lee W.,Chosun University |
Na D.,Gaustek Co |
Park J.,Chosun University
Journal of Ceramic Processing Research | Year: 2012
An oxygen sensor for an automobile exhaust system was integrated by planar technology. Powders of perovskite SrTi1-xFexO3-δ were synthesized by a sol-gel method. Micro-powders to compare the properties of powders were also prepared by a solid state reaction after mixing of commercial reagents of SrCO3, TiO2, and Fe2O3. A paste based on nano- and micro-powders was prepared to make a planar device on an Al2O3 substrate by silk screen printing technology. The phase formation and microstructure were analyzed by XRD and SEM, respectively. O2 sensing and electrical properties were measured as a function of thermal treatment conditions, atmosphere, time and temperature. The precursor was transformed into SrTi1-xFexO3-δ at 800~1100 °C in ambient atmosphere. Zero TCR(temperature coefficient of resistance) for perovskite SrTi1-xFexO3-δ powders was measured over 600 °C. There were no interference effect to CH4, CO, NO2 and CO2, but an excellent response and recovery characteristics with oxygen concentration.