Sensor combining eddy current and permanent magnet disturbance flexible array technology

Abstract

The invention discloses a sensor combining eddy current and permanent magnet disturbance flexible array technology, wherein an array type eddy current detection coil is etched on a polyimide film, anda magnetic sensitive element array for permanent magnet disturbance detection is welded on a flexible circuit board; a flexible array sensor is formed depending on the flexible characteristic of thepolyimide circuit board. The flexible array sensor is coated on the outer surface of a rubber skeleton, and because the rubber has the characteristic of flexible deformation, the array sensor can be well coupled with a complex curved surface to perform nondestructive testing on defects of cracks and the like on the surface and the subsurface of a ferromagnetic component. According to the invention, the eddy current receiving coil and the permanent magnet disturbance detection element are arranged in a spatial staggered manner, so that the spatial resolution of the array sensor is improved. Theeddy current and the permanent magnet disturbance array successively detect the same defect along the scanning direction, decreasing the false negative and the false positive of defects.

Description

technical field [0001] The invention relates to a flexible and bendable sensor with an array structure combined with eddy current and permanent magnet disturbance technology, which is mainly suitable for non-destructive detection of complex surface and subsurface defects of ferromagnetic components. Background technique [0002] Eddy current testing technology is a non-destructive testing method that uses the principle of electromagnetic induction to non-destructively evaluate some properties of conductive materials and their workpieces, or find defects by detecting the changes of induced eddy currents in the tested workpiece. Eddy current is when a conductor is placed in a changing magnetic field, because there is a vortex induced electric field around the changing magnetic field, the induced electric field acts on the free charge in the conductor, causing the charge to move and form an eddy current. The induced eddy current produces a magnetic field opposite to the origina...

AI Technical Summary

Problems solved by technology

For curved surface components, using eddy current testing technology, it is difficult to ensure that the lift-off distance remains unchanged during the testing process, and signals similar to defects will appear when lift-off jitter occurs, so misjudgment is prone to occur

The same problem exists for the permanent magnetic disturbance technology. The vibration of the lift-off distance will affect the detection ability and effect, especially when detecting complex metal surfaces with changing curvatures, such as gears, racks, stepped shafts, etc.

Moreover, the method of using a single detection element in the detection process has the disadvantage of low detection efficiency

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