Eddy Current Testing Technology Is Crucial for Detecting Surface Cracks and Defects in Mechanical Components

Eddy current testing machine uses electromagnetic induction principle to detect surface and near-surface defects of conductive components. The principle is to use excitation coils to generate eddy currents in conductive components, and use detection coils to measure the changes in eddy currents, thereby obtaining relevant information about component defects. Depending on the shape of the detection coil, it can be divided into three types: through-type (used for testing wires, rods, and pipes), probe-type (used for local surface inspection of components), and insert-type (used for internal inspection of pipe holes).

Application of Eddy Current Testing Machine

Eddy current testing machine is portable and suitable for online and offline testing of various metal parts, car parts, metal pipes, bars, and wire.It can be used for automatic testing of other mechanical components such as inner wall of pipes, anvil plates, bearing rings, plate holes, square billets, and round billets.

It has relatively independent testing channels and can drive a combination probe consisting of absolute and differential coils. The testing channels simultaneously carry out data acquisition to detect longitudinal cracks, transverse defects (such as slag), hidden cracks, and other axial defects with high sensitivity in metal pipes, bars, and wire produced.

Detection of eddy current testing machine in technological processing

The detection of defects such as cracks on the surface of mechanical parts is essential to ensure their reliability and safety. Visual inspection alone is no longer sufficient, thus the demand for testing the processing surface of workpieces has increased. To achieve the required quality on the production line, the non-contact measurement method of eddy current testing machine and the full inspection system for short-term testing of produced components are essential.

Therefore, the use of eddy currents in conductors for various testing is an electromagnetic induction inspection, and its typical application is eddy current testing. The detection of eddy current testing machine is to bring the conductor close to a coil with alternating current. The coil establishes an alternating magnetic field, which passes through the conductor and produces electromagnetic induction. The eddy currents in the conductor also generate their own magnetic fields, the change of which changes the strength of the original magnetic field and causes a change in the voltage and impedance of the detection coil. When a defect appears on the surface or near the surface of the conductor, it will affect the intensity and distribution of eddy currents of the eddy current testing machine, and the change in eddy currents will indirectly inform the presence of an internal defect in the conductor.

Due to different shapes of test pieces and different detection positions, the shape of the inspection coil and the way of approaching the test piece are not exactly the same. In order to meet various testing needs, people have designed various types of detection coils and eddy current testing instruments.