Pulsed eddy current probe based on rotating blade-shaped excitation coils
When using pulsed eddy current for crack detection,the disturbances generated by microcracks in the induced eddy currents are weak,resulting in a low signal-to-noise ratio in the detection signal.On the other hand,when scanning cracks in multiple directions with a conventional pulsed eddy current probe,it is difficult to achieve maximum sensitivity and determine the crack orientation.This paper proposed a detection method using a mechatronic rotating pulse eddy current probe,which achieved high-sensitivity detection of microcracks in multiple directions.The blade-shaped excitation coil exhibited significant magnetization and directionality.After the mechatronic high-speed rotation of the excitation coil,detection and receiving signals were obtained at different angles.These received signals were then differentially compared with a reference signal to extract small peak variations,creating a map of the relationship between angle position and peak variation.The results of experiment verification and testing indicated that the probe based on the blade-shaped excitation coil rotating within a hollow receiving coil not only had the capability to distinguish crack depths at the sub-millimeter level but also can determine the orientation of cracks with an error of±5°.
万方数据
维普
