Study On Preparation And Performance Of Thin Film Thermocouple

In the context of the vigorous development of modern high-tech technologies,the fourth generation of initiating explosive devices-MEMS initiating explosive devices has made considerable development,and the dynamics of the ignition temperature There are new requirements for measurement.Ignition temperature is an big indicator of the work performance of initiating explosive devices.Testing it and determining the ignition point is very important to the improvement and application of initiating explosive devices.Aiming at the dynamic test of the ignition temperature of micro-initiating explosives,this paper is based on high-temperature thin-film thermocouples.After parameter optimization and simulation verification,a micro-temperature sensor with high temperature stability and fast dynamic response is designed.Mainly completed the following three parts of work:（1）The preparation technology and properties of thin film thermocouple were explored,with emphasis on the preparation and properties of Pt-Rh10/Pt thin film thermocouple.A Pt-Rh10/Pt thin-film thermocouple with a coupling size of≯1mm and a thickness of 6μm was fabricated on an Al₂O₃ ceramic substrate by a screen printing process.The morphology and performance evaluation experiments of the prepared sensor samples have been carried out,and their conductivity and adhesion properties meet the design requirements.Using 0.3mm diameter Pt Rh wire and Pt wire as compensating wire,the welding method,bonding method and high temperature resistant inorganic adhesive connection method are discussed in this paper.（2）The static calibration of Pt-Rh10/Pt film thermocouple at 50～600℃and 650～1500℃was completed by using a portable temperature calibration furnace and a horizontal high temperature calibration furnace,respectively.overcomes the connection problem between the thin film thermocouple and the extension wire in the static calibration test at 1500℃,and achieves the technical index of effective temperature measurement at 1500℃.The Seebeck coefficient of the thin film thermocouple is about 10.70μV/℃by fitting the experimental data.The output potential and temperature curve of the thin film thermocouple is basically consistent with that of the standard S type thermocouple.（3）By building a dynamic test platform for the micro-size thin-film thermocouple temperature sensor,the pulsed laser method was used to conduct preliminary research and testing on the dynamic response of the Pt-Rh10/Pt thin-film thermocouple,the dynamic mathematical model was established,and the time constant was measured.The experimental results show that the time constant of the prepared Pt-Rh10/Pt thin film thermocouple is about535μs,it laid the foundation for the test of the ignition temperature of the initiating explosive devices.