Design and Fabrication of Thermocouple Sensors Based on a Ceramic Curved Alumina Substrate

Aplatinum-platinum/rhodiumthick-film thermocouple sensor based on an alumina curved-surface ceramic substrate was designed. The thermoelectric components were prepared by screen printing, which is simple, rapid, and low cost; additionally, screen-printed films have uniform thickness. We investigated the as-fabricatedmorphologies of Pt and Pt/Rh films using scanning electronmicroscopy (SEM) and X-ray diffraction (XRD). The results show that the thermocouple film prepared via this process was reasonably stable at high temperatures. We then repeated the test at 1300 degrees C and then at 1500 degrees C for 10 h to determine its thermal limits. After testing at 30-1300 degrees C thrice, the fabricated thermocouple showed excellent consistency and reusability, with a maximum output voltage of 11.733mV and a Seebeck coefficient of 9.110 mu V/degrees C. Upon testing the thermocouple at 1500 degrees C for 10 hours, the peak voltage output was 12.821mV. Therefore, we concluded that the sensor could be used for temperature monitoring in hostile environments such as measurement of turbine blade surface temperature for aeroengines.

Automated summary

A platinum-platinum/rhodium thick-film thermocouple sensor based on an alumina curved-surface ceramic substrate was designed and tested for stability and repeatability at high temperatures. The sensor showed excellent consistency and reusability, making it suitable for measuring turbine blade surface temperature in aerospace applications.