System and method for measuring magnetostrictive strain of rare earth giant magnetostrictive material

Abstract

The invention discloses a system and a method for measuring magnetostrictive strain of a rare earth giant magnetostrictive material. The method comprises the following steps: lapping the system for measuring the magnetostrictive strain of the rare earth giant magnetostrictive material; measuring the residual magnetism of the giant magnetostrictive rod before demagnetization; under different demagnetization current frequencies and amplitudes, different demagnetization initial magnetic fields are generated to demagnetize the giant magnetostrictive rod; measuring residual magnetism of the giant magnetostrictive rod after demagnetization under the magnetic flux density corresponding to different demagnetization current frequencies and demagnetization initial magnetic fields; calculating the demagnetization efficiency of the giant magnetostrictive rod under the magnetic flux density corresponding to different demagnetization current frequencies and demagnetization initial magnetic fields; the demagnetization current frequency with the demagnetization efficiency meeting the requirement and the magnetic flux density range corresponding to the demagnetization initial magnetic field are selected, and the giant magnetostrictive rod is demagnetized; and measuring the magnetostrictive strain of the demagnetized giant magnetostrictive rod. The system further comprises a system for measuring the magnetostrictive strain of the rare earth giant magnetostrictive material. According to the invention, the repeatability of magnetostriction strain measurement is obviously improved, and the measurement accuracy is improved.

Description

technical field [0001] The invention relates to magnetostrictive measurement, in particular to a system and method for measuring the magnetostrictive strain of rare earth giant magnetostrictive materials. Background technique [0002] As a new type of electromagnetic functional material, rare earth giant magnetostrictive material (Terfenol-D) occupies a huge application market in the field of micro-displacement drive due to its excellent magnetostrictive performance, and is widely used in robotics, ultra-precision machining, Precision instruments and underwater acoustic transducers. [0003] The repeatability of magnetostrictive strain measurement of rare earth giant magnetostrictive materials is one of the most critical factors in product application, and it also marks how accurate the measurement is. From the current experimental data, the magnetostrictive measurement has poor repeatability and low accuracy. Magnetostrictive material is a highly nonlinear material, and i...

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Problems solved by technology

[0004] There have been related studies on demagnetization at home and abroad, but most of them focus on soft magnetic materials such as transformer iron cores. CN102323555 A discloses a multi-beam laser heterodyne measurement of magnetic The method of expansion coefficient, which discloses that when measuring the magnetostriction coefficient, firstly demagnetize the test piece, but does not disclose the specific method of demagnetization, nor does it describe how to perform demagnetization efficiently or whether the demagnetization is successful, and does not quantify the residual Effect of magnetism on the accuracy of magnetostrictive strain measurement

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