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.