Development Of Integral Turbine Ultrasonic Phased Array Scanning Imaging Detection System

Turbine is one of the core components of an aero engine,and often works under complex thermal and mechanical load environments.Therefore,the stability of the turbine is directly related to the safety of the aircraft.The overall turbine studied in this paper is prepared by connecting the turbine disk and the blades using a hot isostatic pressure(HIP)connection process.Due to the particularity of its production process,the inclined connection surface between the disc and the blade is prone to poor connection types.According to the structural characteristics of the turbine,select the detection method of separate transmission and reception,technology of phased array probe transmission and curved probe reception.In this study,the ultrasonic phased array combined with mechanical scanning device was used to automatically detect the overall turbine oblique joint surface,and the corresponding software was used to analyze and image the data to realize the overall scanning imaging detection of the turbine oblique joint surface.Due to the lack of special equipment for ultrasonic phased array automatic scanning imaging of the whole turbine oblique joint surface,this paper develops special equipment for ultrasonic phased array combined with mechanical scanning.The specific work content is as follows:First,the geometric and acoustic characteristics of the overall turbine are analyzed and studied.Using the advantages of ultrasonic phased emission and the acoustic phenomena of reflection,refraction and waveform conversion on the oblique interface of the turbine to analyze the defect identification,and elaborate the same depth imaging amplitude method,the polar coordinate conversion of overall turbine imaging and interpolation algorithm principle.Secondly,use the ultrasonic phased array device PA22 X as the hardware foundation for software development,combined with mechanical scanning device and clamping device to form an integrated turbo ultrasonic phased array scanning imaging detection system.Using the QT development platform,a dedicated turbo imaging detection software has been developed,which has the functions of controlling the transmission and reception of the separate ultrasonic phased array to transmit and receive signals,data acquisition and data processing,and imaging.Finally,the defect imaging effect of the special system is verified by detecting the turbine test blocks with embedded defects at different depths and angles.According to the real-time A-scan waveform diagram,the same depth imaging diagram and the overall turbine imaging diagram of the system detection results,it is analyzed and proved to be practical.The results of the study indicate that the overall turbo-ultrasonic phased array scanning imaging inspection system can be used for defect inspection of the oblique joint surface of the overall turbine.The automatic scanning device can avoid the problems of missed detection and false detection due to manual operation;The amplitude of the reflected echo of the joint surface can determine whether there is a defect;it can detect the defective joint with a minimum equivalent diameter of 2mm and the detection and display effect is intuitive.