Preparation And Performance Research On PDC-SiAlCN Ceramic Based Wireless Passive Temperature Sensors

For this highly sophisticated aircraft engine operation of the device,its internal working environment not only has the characteristics of high temperature,but also has special requirements for high pressure and high speed,if any small failure could have catastrophic consequences,and therefore the engine health management(EHM)is particularly important.One of the key technologies for EHM system design is sensor technology.Among them,the wireless passive temperature sensor has the advantage of being wireless and passive,and it can carry out real-time temperature monitoring on the aeroengine,which is a high-temperature,high-pressure,and sealed environment,and has a good prospect of engineering application.Precursor ceramics have excellent properties such as high temperature resistance,corrosion resistance and radiation,and they have wide bandgap semiconductor characteristics.They are potential excellent materials for semiconductor devices and temperature sensitive pressure sensitive sensors used in harsh environments.The addition of Al in PDC-SiAlCN ceramics can effectively increase the oxidation resistance of ceramics.When PDC-SiAlCN ceramic is used as resonator dielectric and the high-temperature metal is used as the surface metal layer,the resonator formed under the changing temperature ring will cause the resonant frequency of the resonator to change correspondingly due to the change of the dielectric constant of the PDC-SiAlCN ceramic.The relationship between the resonant frequency and the ambient temperature can be obtained by establishing the relationship between the dielectric constant and the temperature.Using polyvinylsilazane(PVSZ)as precursor and aluminum sec-butoxide(ASB)as aluminum source,PDC-SiAlCN ceramics were obtained through cross-linking,ball milling,tabletting,and heat treatment.The structure and properties of ceramics were analyzed.A PDC-SiAlCN ceramic-based wireless passive temperature sensor is designed with PDC-SiAlCN ceramic as the sensing element.The electromagnetic simulation software is used to determine the relevant parameters such as the sensor diameter and the resonant frequency f and the quality factor Q of the sensor.Thickness,grooved antenna length and width dimensions are simulated.According to the simulation parameters,a PDC-SiAlCN ceramic-based wireless passive temperature sensor with a test temperature of 1100? was finally prepared.The influence of different sensor diameters and thickness on the resonant frequency of the sensor was also studied.It is found that the diameter of the sensor element has a great influence on the resonant frequency of the sensor,and the resonant frequency of the sensor decreases with the increase of the diameter of the sensor element;the thickness of the sensor element has little effect on the resonant frequency of the sensor.Through the study of the transmission distance of the sensor,the transmission distance of the sensor can reach 38 mm at room temperature,and the transmission distance can reach 7 mm when the test temperature is 1100?.