航空发动机涡轮叶片涡流自动化检测试验研究

涡流检测技术对工件表面或近表面的缺陷有很高的检出灵敏度，且检测线圈不需与被测物直接接触，可进行高速检测，易于实现自动化。针对航空发动机涡轮叶片的复杂曲面人工检测难度大、效率低等问题，研制了一套六自由度机器人涡流自动化检测系统，该系统可自行对其工作空间、工作表面和运动学的工作特性进行分析研究；设计了多种典型涡轮叶片专用弹压式涡流检测探头，可自适应叶片形貌及叶片安装误差；开展了涡轮叶片检测自动扫查检测试验，优化了涡流检测的激励频率和自动扫查速度。结果表明:可弹压式涡流探头对叶片表面缺陷可自适应涡轮叶片的复杂表面，提高了自动化检测的精度，同时弥补提离变化和安装误差。当激励频率为1.25~1.75 MHz、扫查速度为30 mm/s时，检测灵敏度较高，能有效检出缺陷。相比于人工涡流检测方法，该自动化检测系统提高了叶片的检测效率。

Test Study of Automatic Eddy Current Detection of Aero-engine Turbine Blade

Eddy current detection technology has high detection sensitivity for defects on or near the workpiece surface. The detection coil does not need direct contact with the object to be detected, enabling high-speed detection and easy automation. To address the difficulty and low efficiency of manual detection about complex surface of aero-engine turbine blades, an eddy current automatic detection system featuring 6-degree-freedom robot was developed, which can analyze the working characteristics of its workspace, working surface and kinematics by itself. A variety of special compression eddy current detection probes for typical turbo blades were designed, which can adapt to blade morphology and blade installation error. The automatic sweep test of turbine blade detection was carried out, and the excitation frequency and automatic sweep speed of eddy current detection were optimized. The results show that the vibratile eddy current probe can adapt itself to the complex surface of turbine blades, improving the accuracy of automatic detection, and compensating for the lift variation and installation error. When the excitation frequency ranges from 1250 to 1750 kHz and the sweep speed is 30 mm/s, the detection sensitivity is high enough to efficiently identify the defects. Compared with the manual eddy current detection method, the automatic detection system improves the detection efficiency of the blade.