Researchers Weng Ling, Chang Zhen, Sun Ying, Wang Bowen, and Huang Wenmei of the State Key Laboratory of Reliability and Intelligence of Electrical Equipment and the Key Laboratory of Electromagnetic Field and Electrical Appliance Reliability of Hebei Province jointly built by the Hebei Provincial Ministry, in the 10th issue of 2020 An article in the Journal of Electrotechnical Engineering, introducing a mathematical model of magnetic energy loss under a small hysteresis loop, using the AMH-1M-S type dynamic magnetic property test system to measure the height of Fe-Co-V, Terfenol-D and Fe-Ga alloy samples Frequency hysteresis loop, using the experimental test results combined with the mathematical model to comparatively analyze the variation of the magnetic permeability amplitude, dielectric loss factor, dielectric energy storage and electromagnetic loss of the three materials.
When the frequency of the excitation magnetic field is 50kHz, with the increase of the magnetic induction intensity, the dielectric loss factor of Terfenol-D and Fe-Ga alloy increases approximately linearly, and the electromagnetic loss of the three alloy samples increases. When the magnetic induction intensity is 0.03T, as the excitation magnetic field frequency increases, the magnetic permeability amplitude of Fe-Co-V and Fe-Ga alloys increases first and then decreases, and the medium energy storage of Terfenol-D alloy increases fastest And its electromagnetic loss increases fastest with frequency. The electromagnetic loss of the Fe-Ga alloy is higher than that of the Fe-Co-V alloy within 1-40 kHz, and the electromagnetic loss of the Fe-Ga alloy is lower than that of the Fe-Co-V alloy within 40-60 kHz. The results of this paper provide a basis for the analysis of the electromagnetic loss of magnetostrictive materials and the design of high-frequency devices.
Advanced soft magnetic materials show high frequency, high magnetic flux density and the coexistence of miniaturization and multi-function development pattern. Some advanced electrical soft magnetic materials have developed rapidly, especially Fe-Co-V, Terfenol-D Magnetostrictive materials represented by Fe-Ga alloys are widely used and have a profound influence on power devices.
Fe-Co-V alloy has extremely high saturation magnetic induction intensity (2.4T), Curie temperature (980～1100℃), large saturation magnetostriction coefficient (60～100×10-6), suitable for light weight and volume Small aviation components (such as relays, electromagnets, micro motors, etc.), but the alloy's resistivity (0.27Ωm) is low, and it is greatly affected by magnetic energy loss when used at high frequencies. Terfenol-D alloy is a magnetostrictive material with large magnetostriction coefficient (2000×10-6), high energy density and fast response speed. It has significant advantages in high-power ultrasound (f ≥20kHz) and sonar. However, the alloy material generates hysteresis during high-frequency driving, which affects the energy conversion efficiency of the device.
Fe-Ga alloy has the advantages of high magnetic permeability, high stress sensitivity, and low saturation magnetic field. It is widely used in the field of new sensor devices and vibration power generation. The key index that affects the performance of Fe-Ga alloy devices is the magnetic properties of Fe-Ga alloy. Conductivity and electromagnetic losses [9-10]. Therefore, when three different magnetostrictive materials are used for device design in the high-frequency field, the analysis of high-frequency magnetic energy loss is the basis for the design and application of related alloy device structures.
• Some scholars studied the high-frequency magnetic properties of the ring-shaped Galfenol alloy, focusing on the analysis of the relationship between the magnetic permeability, coercive force, residual magnetic induction strength and loss with frequency. • Some scholars have found that the curve of the electromagnetic loss of Tbdyfe alloy with frequency is parabolic, and the eddy current loss accounts for the main part of the loss. A new type of composite material was prepared using Tbdyfe alloy powder. The loss is hysteresis loss. • Some scholars have measured the change of magnetic permeability with the strength of the external magnetic field in the FeCoB thin film of soft magnetic materials in the frequency range of 0.2 to 8 GHz. •Some scholars established the magnetic field function of super magnetostrictive materials under AC excitation, found that the driving frequency will affect the size and hysteresis of the magnetic field, and obtained a mathematical model suitable for the calculation of magnetic energy loss at low and medium frequencies, and analyzed the driving magnetic field frequency It affects the complex magnetic permeability, hysteresis characteristics of the magnetic field and magnetic energy loss, but the electromagnetic characteristics of the material at high frequencies are not analyzed in this article. • Some scholars have combined the traditional J-A hysteresis model with the transient eddy current and residual loss models to establish the J-A dynamic hysteresis model, which requires more parameters and less application in actual engineering. •Some scholars have proposed an improved iron loss calculation model, which can reflect the changes of the eddy current skin effect, dynamic hysteresis loop and domain wall motion in the laminated material at high frequency and high magnetic density, and the experimental measurement results and calculations The results have a good correspondence. • Some scholars have improved the Steinmetz loss equation and proposed a method for predicting the loss of different soft magnetic materials under symmetric and asymmetric magnetic induction waveforms. The experimental measurement and calculation results are compared to prove the engineering practicability of the method. •Some scholars have designed a dual-coil iron-gallium alloy hysteresis telescopic transducer, and analyzed the energy storage, electromagnetic loss, and mechanical energy changes of the transducer at different magnetic field frequencies using the conversion relationship between magnetic energy and mechanical energy. Due to the diversity of magnetostrictive materials and the complexity of hysteresis characteristics at high frequencies, there is less comparative analysis of the loss characteristics of different magnetostrictive materials with frequency. Researchers of Hebei University of Technology aim at the material selection problems encountered in the design process of magnetostrictive devices under the same engineering background, from the magnetic permeability, dielectric loss factor, dielectric energy storage and electromagnetic loss of different magnetostrictive materials Contrast and analyze the magnetic energy performance of Fe-Co-V, Terfenol-D and Fe-Ga alloys.
The magnetic energy loss model of the small hysteresis loop is introduced, and the AMH-1M-S type dynamic magnetic property test system is used to measure the typical magnetostrictive materials Fe-Co-V, Terfenol-D, and Fe-Ga alloy at different excitation magnetic field frequencies and different The dynamic hysteresis loop under the magnetic induction intensity, comparative analysis of the influencing factors of the magnetic energy loss of the three materials under different conditions, provides a theoretical and experimental reference for the optimal design and application of new magnetostrictive devices.
The researchers finally concluded the following:
1) When the frequency of the alternating excitation magnetic field is 50kHz and the magnetic induction applied to the sample is 0.01～0.03T, the magnetic permeability of Fe-Co-V, Terfenol-D and Fe-Ga alloy increases by 6.44% and 21.57, respectively % And 31.72%;
The loss factor of Fe-Co-V alloy has less fluctuation, while the loss factors of Terfenol-D alloy and Fe-Ga alloy both increase approximately linearly, increasing by 44% and 59.52% respectively; Fe-Co-V, Terfenol-D The electromagnetic losses of Fe-Ga alloy and Fe-Ga alloy increased by 7.96 times, 9.26 times and 8.48 times respectively. Under the same magnetic induction intensity, the electromagnetic loss of Terfenol-D alloy is the largest and that of Fe-Ga alloy is the smallest.
2) When the maximum magnetic induction intensity is 0.03T and the excitation magnetic field frequency is 1 ~ 60kHz, the magnetic permeability of the Fe-Ga alloy is the largest, and the smallest of the Terfenol-D alloy; the dielectric loss of the Fe-Co-V alloy and the Fe-Ga alloy The factors are gradually increasing, and the dielectric loss factor of Terfenol-D alloy increases first and then tends to be stable;
The energy storage of Fe-Co-V, Terfenol-D and Fe-Ga alloys is increased by 78.73 times, 112.40 times and 67.25 times respectively; when the excitation magnetic field frequency is 1-20kHz, Fe-Co-V, Terfenol-D and Fe- The electromagnetic loss of Ga alloy has increased by 152.03 times, 33.59 times and 29.39 times respectively. The electromagnetic loss of Terfenol-D alloy is the largest and that of Fe-Co-V alloy is the smallest;
When the excitation magnetic field frequency is 20 ~ 60kHz, the electromagnetic losses of Fe-Co-V, Terfenol-D and Fe-Ga alloys increase by 7.42 times, 3.26 times and 4.11 times respectively.