Method for detecting non-uniformities of magnetic materials and device for effecting same

摘要

The method for detecting non-uniformities of magnetic materials resides in the use of the direct and inverse electromagnetic-acoustic conversion, effected in the zone of magnetic non-uniformities of magnetized articles. The method is characterized by effecting said conversion in an intermediate layer located in the vicinity of the material being inspected. As the intermediate layer, materials with great values of dynamic magnetostrictive constants are used. The use of the intermediate layer of a predetermined configuration enables estimation of the non-uniformity value not only singularly by the amplitude of the established elastic vibrations, but also by the number of recurrent pulses whose pulse-height distribution is conditioned by the damping factor of the intermediate layer. In the given device, as distinct from the conventional noise-suppressing devices, operating on the principle of decoding the coded signals, the parameters of the code are defined by the material and structure of the intermediate layer.