Development Of PtRh6 High Temperature Film Strain Gauge For Turbine Stator Blade Surface

With the development and progress of China’s aviation industry,the adaptability of aerospace equipment to harsh working conditions also needs to be gradually improved.Therefore,it is very critical and necessary to detect the health level of aerospace key equipment.At present,how to accurately measure the strain value in the environment above 600℃is still a big problem in the development of equipment.The ordinary resistance strain gauge has the characteristics of large volume,complicated installation steps,and is greatly affected by the temperature,poor temperature compensation effect and so on.Therefore,this paper takes the aero-engine turbine stator blade as the research object,aiming at the micro strain sensor based on the film strain gauge In order to break through the basic scientific problems in the manufacture of high-temperature thin-film strain gauges and provide support for the development and application of China’s aviation equipment,we should carry out systematic research from the aspects of structure scheme,preparation process,performance characterization and comprehensive testing.The main research contents are as follows（1）The steady-state temperature field and stress field of turbine stator blade of aviation internal combustion engine are calculated by COMSOL finite element simulation software to determine the temperature and deformation form at the peak of surface stress.（2）The high temperature characteristics and geometric structure of the sensitive layer are analyzed by using the finite element method,so as to determine the material for preparing the sensitive layer and the optimal design size of the sensitive layer,and calculate its resistance temperature coefficient and sensitivity.（3）The structure of Al₂O₃/Zr O₂/Al₂O₃/Zr O₂ composite insulation layer was determined by surface morphology characterization experiment,composition characterization experiment and high temperature insulation characterization contrast experiment.The insulation resistance of the structure at room temperature and 1000℃is 8.14×10⁵MΩand 3.3MΩrespectively.The heat treatment experiment of four layers of composite insulating layer in atmospheric environment shows that the heat treatment process of 600℃and 3 h makes the process of composite insulating film reach the best,and the insulation resistance at room temperature and1000℃is 1.86×10⁴MΩand 25.8MΩrespectively.（4）PtRh6 high temperature thin film strain gauge with integrated function film was prepared by photolithography and magnetron sputtering technology,and its sensitivity and temperature coefficient of resistance were characterized.Comparing the element composition ratio and high temperature resistance change rate of the sensitive layer before and after annealing at 900℃,it is found that the oxygen content of ptrh6 increases slightly after heat treatment,and the initial increment is higher than that before annealing;the resistance temperature coefficients before and after annealing are 301.02ppm/℃and 88.52ppm/℃respectively.The sensitivity of PtRh6 high temperature thin film strain gauge is 1.09 ppm/με.