Research And Application Of Metal Surface Creak Detection Based On Eddy Current Effect

As one of the most widely used materials,metal has the advantages of high toughness and high strength.However,when there are hidden defects in the metal,it will bring huge security risks to actual use.Therefore,how to find and locate these defects is of great research significance for improving the service life of metals and reducing the safety hazards in actual production.To this end,the following work has been carried out:First of all,this paper analyzes the detection methods and research status of non-destructive testing technology.According to the comparison between eddy current testing and other testing methods(ultrasonic testing,magnetic particle testing,penetration testing,etc.),eddy current testing is faster and the testing process Without contact,the eddy current testing method is particularly sensitive to cracks on the metal surface,so the eddy current testing method is more suitable for defect detection on the metal surface.Secondly,through the study of the principle of eddy current testing,this paper draws the main influencing factors(excitation frequency,coil parameters,lift-off distance,etc.)that affect the eddy current testing results,and simulates the impact of various factors on the results.It is found that when the detection frequency is 10000 Hz,the sensor has a good effect on detecting cracks;when the coil size is 12 mm in outer diameter,4 mm in inner diameter,and 10 mm in thickness,the coil is more sensitive to cracks.At the same time,using the selected parameter coil to detect different cracks,it is found that in the smaller crack width,the voltage increases with the crack width;when the crack height is within 4mm,the crack height is positively correlated with the output voltage;At 10000 Hz,the sensor has a good detection effect for cracks of different depths.Finally,according to the actual detection needs,this paper selects a new method of surface detection(rotation body rotation,sensor movement)to replace the sensor on the existing instrument for spiral motion detection,which improves the detection speed and reduces the manufacturing accuracy.Connect the sensor to the computer,use the virtual instrument to write a program block diagram,and perform noise reduction processing on the signal.Scanning and detection of the rotating body with cracks were carried out to judge the cracks of the ferromagnetic components more accurately.It was verified that the output voltage was proportional to the size of the cracks within a certain range.The high sensitivity of the experimental device to cracks in this paper proves that the device can be used in actual detection,which reduces the cost of surface detection of the metal rotating body and increases the service life of the metal rotating body,which is of great significance to actual production and life.