Design and performance evaluation of an all-ceramic high-temperature test sensor

Abstract

To meet the test requirements for the surface temperature parameters of next-generation ceramic matrix composite equipment components, this study designed and fabricated an all-ceramic material high-temperature test sensor, including a substrate, sensitive layer, and protective layer. The sensor was prepared using the thick-thin film integration process. The ITO-In2O3 thick film thermocouple was prepared on ceramic substrate using screen printing technology, and the Al2O3 thin film protective layer was prepared by pulsed laser ablation and the sol-gel method. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to study the microstructure, phase, surface element composition and chemical transition state of the prepared thermocouple. The results show that the sintered thermocouple has a compact structure and good electrical conductivity. Static and dynamic test platforms were built to test the performance of thermocouple, and test results show that the prepared thermocouple has good repeatability and stability in the temperature range of 25–1300 °C. The average Seebeck coefficient reached 129.80 μV/°C. In the thermoelectric stability evaluation experiment (1300 °C for 8 h), the peak output voltage was 153.2 mV. The limit test temperature of the thermocouple reached 1500 °C. When the temperature difference was 1382 °C, the peak output voltage was 169.974 mV. The dynamic properties of the sensor were studied using pulsed laser heating, and the results showed that the dynamic response time constant of the thermocouple was 3.52 ms.