The stability and repeatability of high temperature electrical properties of SiAlCN ceramic sensor heads

To produce the sensor heads, the SiAlCN green body with platinum electrodes was pyrolyzed at 1000 °C for 4 h. Its stability and repeatability of electrical properties were tested in the air at high temperature. According to the results, the several SiAlCN sensor heads exhibited similar resistance with the increasing temperature range of 650–900°C, indicating that their electrical properties tend to be stable in the high temperature region. When the temperature was changed from 650 °C to 680 °C for 10 cycles, the resistance of the sensor heads varied from 3% to 4‰ namely the corresponding temperature of the sensor heads varied by 3–4 °C. However, their resistance only varied from 4‰ to 6‰ with 6 cycles in the temperature range of 685–700 °C, demonstrating that the corresponding temperature of the sensor heads was changed by nearly 1 °C. The cycling tests in both temperature ranges verified that the SiAlCN sensor heads have excellent repeatability. Also, the SiAlCN sensor heads exhibited excellent stability and repeatability when the resistance slowly changed with the temperature gradually varying from 675–700 °C to 700–725 °C in the air. Accordingly, the SiAlCN sensor heads have excellent stability and repeatability, which can serve as temperature sensors to monitor the temperature in extreme environments exposed to oxygen at high temperature.