SU1456864A1 - Method of magnetic noise structurescopy of ferromagnetic materials - Google Patents

Abstract

The invention can be used for non-destructive testing of structure-clamping parameters of ferromagnetic materials by the Barkhausen effect method. The aim of the invention is to improve the accuracy of control due to the correct selection of the magnetization mode and the recorded informative parameter. The product is re-magnetized by a trapezoidal field with a different residence time t, and t2 is in saturation states, the difference 4N N. —N is the number of Barkhausen jumps in the upstream N, and downward N branches of the hysteresis loop of the ferromagnet B f (H), and based on the dependence 4N f (, -t), the result of the control is determined. 3 il. sfi (L

Description

The invention relates to instrumentation technology and can be used for non-destructive testing of structure-dependent parameters of ferromagnetic materials using the Barkhausen effect method.

The purpose of the invention is to improve the accuracy of control of structure-dependent parameters by improving the magnetization reversal mode and selecting a new informative parameter in the form of the difference in the number of Barkhausen jumps recorded in the ascending and descending branches of the loop.

Figure 1 shows a block diagram of a device implementing the method of magnetic noise-noise struc- turoscopy in figure 2 — oscillograms of signals j in FIG. 3 — experimental graphs. .

The device includes serially connected generator 1 of trapezoidal pulses, inductive transducer 2, first switch 3 and counter 4, connected in series to the first driver 5 pulses and the second switch 6 connected between the second output of generator 1 and the second input of counter 4, and the second driver 7 connected between the third input of the generator 1 and the second input of the switch 3, the output of the converter 2 is also connected to the second input of the switch 6. The controlled product 8 is connected via an electromagnet nitolny floor with the converter 2.

The complexity of the method is based on an experimentally established fact

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Claims (1)

The method of magneto-noise structuroscopy of ferromagnetic materials, which consists in the magnetization reversal of a product by a trapezoidal pulse train and registration of Barkhausen jumps on the ascending and descending branches of the hysteresis loop, characterized in that, in order to improve the accuracy of control of structure-dependent parameters, a different time t is set, and the residence time of the product in states with maximum magnetization, respectively, with its direct and reverse magnetization reversal with a constant rate of change field H so that dH / dt = const ^ 0, the difference in the number of Barkhausen jumps on the ascending and descending branches of the hysteresis loop is recorded, depending on which the controlled parameter is determined by the value Δt = t. Figure 1 A L Π <'t /TO Π Π „w t