Giant Magnetostrictive Material Research Articles

Magneto-Mechanical Coupling Analysis of Automobile Brake by Wire System Based on Giant-Magnetostrictive Actuator

Addressing the drawbacks of traditional automotive braking systems, including long hydraulic lines, heavy weight, and slow response speed, a new type brake by wire system based on giant-magnetostrictive material is proposed, which consists of giant-magnetostrictive actuator module and mechanical drive module. In this paper, CATIA software is used to establish a three-dimensional model of the brake. In order to verify the reliability of the model, giant-magnetostrictive actuator is taken as the research object, and COMSOL software is used to simulate different working conditions of automobile braking. A Magneto-mechanical coupling model was established and Magneto-mechanical coupling analysis of the actuator was carried out. The simulation results show that the aluminum shell material is superior to the 45 steel shell material. The inductance direction of the actuator is approximately elliptical from top to bottom, with uniform distribution of magnetic flux density and stress. The output stress is 5e4N/m2, and the maximum elongation is 0.1071mm. Finally, the driving efficiency of GMA was verified on an optical isolation platform, and comparative experiments were conducted before and after optimization using instruments such as laser displacement samplers, Tesla meters, and force sensors. The experimental results indicate that by optimizing the housing material and structure of the actuator, the displacement increased from 0.05188mm to 0.1003mm, magnetic induction increased from 42.9mT to 79.9mT, resulting in an increase of 41.6% and 42.7% respectively, and the maximum output force was 4752.3N. It makes a certain contribution to the application of GMA to automotive braking field and further proves the effectiveness of GMA in the application of automobile brake by wire system.

Research on multi-scale hysteresis constitutive model of giant magnetostrictive materials considering multi-field coupling

The magnetization and magnetostrictive strain of giant magnetostrictive materials exhibit a complex nonlinear trend under the coupling of multiple fields, including magnetic field, temperature field, and prestress field. To enhance prediction accuracy, we propose a three-dimensional magnetic-thermal-force coupled nonlinear multi-scale hysteresis vector model. This model is derived from the principles of thermodynamics and continuum mechanics, taking into account the interactions among magnetic domains, grains, polycrystals, and macroscopic scales. It combines the volume-averaging principle of magnetic domain microscopy with the generalized Jiles-Atherton hysteresis model. The predicted hysteresis magnetization and magnetostrictive strain curves obtained from this model are in good agreement with experimental results. By analyzing the predicted hysteresis magnetization and magnetostrictive strain under different conditions, we demonstrate that our proposed model can comprehensively describe the effects of temperature and prestress on the multi-field coupled hysteresis behaviors of giant magnetostrictive materials. Moreover, it provides theoretical guidance for both macroscopic and microscopic optimization in designing active devices incorporating super magnetostrictive materials.

Modeling and simulation of magnetostrictive actuators based on ΔE effect Preisach model

Based on the classical Preisach model, combined with the magneto-mechanical coupling effect of Giant magnetostrictive materials (GMM), this paper introduces the Everett function to optimize the classical Preisach hysteresis model and improve its accuracy. By importing dynamic parameters, the dynamic Preisach hysteresis model is established. Combined with the constitutive model of GMM, a dynamic Preisach hysteretic nonlinear magnetostrictive actuator model based on the ΔE effect is established. Then, the finite element simulation is carried out by Comsol software and compared with the theoretical model simulation. The results show that the error between the magnetostrictive strain of the established hysteresis model and the finite element simulation results is less than 100 ppm, which verifies the accuracy of the proposed model. Finally, the curves of magnetic field intensity, magnetic induction intensity, magnetization, magnetostrictive strain and ΔE effect of GMA are obtained by using this model.

Energy harvesting using magnetostrictive materials: Effects of material anisotropy and stress multiaxiality

Low-frequency vibrations are common as background noise in urban and industrial environments. They originate from natural or artificial sources: road vehicles, industrial machinery, wind, etc., and constitute a ubiquitous energy source. In the framework of energy harvesting, magnetostrictive materials are an attractive alternative solution to the brittleness and geometrical limitations of piezoelectric materials. While numerous previous works dealt with uniaxial stress on selected materials, the exploration of the effects of multiaxial loadings and material anisotropy has not yet been investigated as a way to improve the performance of low-frequency vibration energy harvesting systems. In this work, we investigated the capability of grain-oriented electrical steel in an energy-harvesting context. This material has been selected as a model material, notably as it is abundant and cost-effective. It shows limited magnetostriction but significant elastic, magnetic, and magnetostrictive anisotropy. We combined experimental and predictive simulation results to discuss the possibility of increasing the levels of harvested energy by playing with the orientation of magnetic and mechanical stimuli. Various orientations of magnetic field and mechanical stress were considered with regard to the rolling direction of the material. Unexpectedly high energy density amounts, up to 10 mJ·cm−3, were obtained, competing with giant magnetostrictive materials like Terfenol-D or Galfenol.

(Invited) Magneto-Mechanical Micro-Nano Devices with Electrodeposited Magnetostriction Films

Microsystems play an important role in IoT sensors and actuators in the recent information and communication society. Among these, actuators are important elements used in transmitters, acoustic devices, and optical elements, and for those devices, piezoelectric thin films have been used widely. Magnetostrictive materials are expected to have even greater actuation performance than that of the piezoelectric films, but in the magnetostrictive films integration technologies with a high performance have not yet been fully developed. We have developed the film deposition technologies for magnetostriction materials by electrodeposition and apply them to actuators and sensors [1,2]. The FeGa, TbDyFe, and FeCo magnetic materials are known as giant magnetostriction materials [3]. In this study, the film deposition method for these materials have been developed by electrodeposition. Tbe electrodeposition of rare earth elements is generally considered to be difficult, but in this study, by using Fe chelate as a catalyst, the magnetic films containing Fe and rare earth elements have been successfully deposited, and large magnetostriction are achieved. The TbDyFe films show magnetostriction of ~1000 [1]. In addition, large volume magnetostriction has been observed in these amorphous materials. The magnetostrictive materials are known to have a reverse magnetostriction effect, in which the magnetization of the magnetic material changes when it is subjected to strain. They are known to work as strain sensors based on magnetic measurements. In order to demonstrate the strain sensing, a bi-material cantilever of FeGa/Si with a Si Hall sensor integrated on the support has been developed, as shown in Fig. 1 [2]. The vibration of the cantilever can be detected from the magnetization change using the integrated Hall sensor. On the other hand, magnetostrictive actuators generally require an electromagnet to drive them, making them difficult to miniaturize the system. Therefore, an attempt has been made to drive magnetostrictive thin films by injecting spins into them using the spin Hall effect, giving angular momentum to the spins of magnetic materials and changing the spin fluctuations [4]. It is found that a large strain can be generated by spin injection into the TbDyFe film. The above results show that high-performance magnetostrictive films can be deposited by electrodeposition and can be applied to strain sensors and spin-current driven actuators, and are expected to be applied to the development of novel sensors and actuators [5].References H. Shim, K. Sakamoto, N. Inomata, M. Toda, N. V. Toan and T. Ono, Magnetostrictive Performance of Electrodeposited TbxDy(1−x)Fey Thin Film with Microcantilever Structures, Micromachines 11, 5 (2020) 523.T. Ezura, N. Inomata, T. Ono, Integration of Magnetostrictive Microsensor With Hall Element for Microstructure Resonant Detection, 21st International Conference on Solid-State Sensors, Actuators and Microsystems (Transducers), (2021) 418-421.Mohammad Akita Indianto, Masaya Toa, Takahito Ono, Comprehensive study of magnetostriction-based MEMS magnetic sensor of a FeGa/PZT cantilever, Sensors and Actuators A 331, (2021) 112985.H. Arisawa, H. Shim, S. Daimon, T. Kikkawa, Y. Oikawa, S. Takahashi, T. Ono, E. Saitoh, Observation of spin-current striction in a magnet, Nature Communication 13 (2022) 2400.M. A. Indianto, M. Toda, T. Ono, Development of assembled microchannel resonator as an alternative fabrication method of a microchannel resonator for mass sensing in flowing liquid, Biomicrofluidics 14, (2020) 064111. Figure 1

Development of Giant Magnetostrictive Materials for an Active Noise Control System in an Ultracompact Electric Vehicle

Recently, ultracompact electric vehicles (EVs) have begun to be sold, instead of general vehicles equipped with gasoline engines, for transportation. However, because the outer plate of an ultracompact EV has low rigidity, the road noise generated by rotation and the wind noise generated from the vehicle's projection shape are transmitted to the inside of the EV. This interior noise reduces the ride comfort for passengers. Therefore, an active noise control (ANC) system was proposed for controlling noise transmitted from the outside of the EV. The proposed ANC system was configured to control the sound generated using a giant magnetostrictive actuator on the wall surface in the cabin of the EV, instead of a vehicle installation speaker.In this study, Tb, Dy, and Fe powders, which are giant magnetostrictive materials, were mixed and mechanically alloyed to produce multiple giant magnetostrictive materials to be used in the proposed ANC system. The displacement of each alloyed giant magnetostrictive material was measured. In addition, each alloyed material was analyzed using X-ray diffraction and their crystal orientation was confirmed.

Domain engineering in ferromagnetic morphotropic phase boundary with enhanced and non-hysteretic magnetostriction: A phase-field simulation

Giant and non-hysteretic magnetostriction is critical for magneto-mechanical applications, such as transducers, sensors, and actuators. In this work, the introduction of domain engineering into the single crystals near the ferromagnetic morphotropic phase boundary (MPB) is achieved through phase-field simulation, with the aim of exerting control over domain configuration and magnetostriction. It is found that intermediate external magnetic fields applied along non-easy magnetic axes during the nucleation stage can significantly affect the subsequent domain growth and evolution kinetics. The simulations reveal a domain wall broadening mechanism to explain the significantly improved non-hysteretic magnetoelastic responses observed in engineered tetragonal crystals. Our simulation results additionally demonstrate a discernible correlation between the domain wall densities and external fields in the engineered tetragonal domain. This research provides a potential pathway for the advancement of giant and non-hysteretic magnetostrictive material designs.

Prediction of magnetic energy loss of Giant magnetostrictive materials under different prestresses, AC excitations and DC biases

Magnetic energy losses of giant magnetostrictive material (GMM) significantly depend on a number of factors including prestresses, AC excitations, and DC biases. The existing magnetic energy loss prediction models require further optimization to account for the sensitive magnetic hysteresis of GMM. A magnetic energy loss prediction model that can adapt to different operating conditions is very essential for GMM applications. Herein, the dependency of magnetic energy losses to the operation conditions is interpreted by the parametric variations of the Jiles-Atherton model. A novel four-step parameter identification procedure with great generalizability is proposed. In particular, the combined effects of three external conditions on model parameters are considered. The measurement and simulation data of major hysteresis loops, symmetric minor hysteresis loops, and biased minor hysteresis loops under different operating conditions are compared, which verified the effectiveness of the modified model. Finally, the magnetic energy losses of biased minor hysteresis loops of GMM at different frequencies are calculated using the modified model and compared with the measured data. The average relative error is 5.59 %, and the maximum relative error is 12.05 %.

Characterization and Multiscale Modeling of the Magneto-Elastic Behavior of Galfenol

The properties of giant magnetostrictive materials in actuation, sensing, or energy harvesting applications are very sensitive to pre-stress levels. This work presents the experimental characterization of the magneto-mechanical behavior of Galfenol under static compressive and tensile stress. The results show the high sensitivity of both magnetization and strain to the stress level. A multiscale modeling tool is then used to model the measured magnetic and magnetostrictive responses. The results demonstrate the ability of the proposed multiscale approach to capture the magneto-elastic effects with a very limited number of material parameters.

Analysis of energy conversion capability among various magnetostrictive materials for energy harvesting

This work addresses vibrational energy harvesting using magnetostrictive materials. In this field, materials with exceptional magneto-mechanical coupling properties (e.g. Galfenol, Terfenol-D) have attracted significant attention. Only a few magnetostrictive materials have been tested in devices, however, leaving the actual influence of these materials’ properties on the energy harvesting device open to question. This work compares an extensive range of ferromagnetic materials through analysis of their magnetic behavior under static stress. To enable fair comparison of the materials, a model was developed to interpolate their magnetic anhysteretic curves under fixed stress of σ = ±50 MPa. The energy harvesting process was then simulated using a theoretical Ericsson thermodynamic cycle, where the area represents the energy density. This approach estimates the ultimate energy density of the materials using a fair approach, without placing conditions on the applied magnetic field. The correlation between ultimate energy density and the magnetoelastic coefficient show that highly magnetostrictive materials achieve higher ultimate energy densities, as expected. In the low field range, it is however concluded that all materials exhibit energy densities of the same order of magnitude. Secondly, the magnetoelastic coefficient versus excitation field characteristics revealed an optimal bias magnetic field for each material. Finally, for realistic implementation, the paper considers a pre-stress in combination with a bias magnetic field and the small dynamic variations that result from currents induced in surrounding coils. A model was developed and revealed an optimum output energy density that was independent of the geometry and the coil. An energy harvesting figure of merit was then defined to enable a final comparison of the materials, encompassing both material characteristics and realistic applications. Under these working conditions and with all costs considered, some low-magnetostriction materials appeared able to compete with giant magnetostriction materials.

Facilitated reversible domain switching at multiphase boundary in periodically orthogonal poled KNN‐based ceramics: Strain versus non‐180o domain

AbstractAlthough many approaches have been implemented to tailor the strain in potassium sodium niobate (KNN)‐based ferroelectrics, they still suffer from poor strain compared to shape memory alloys and giant magnetostrictive materials. Herein, a strategy of periodic orthogonal poling is implemented in KNN‐based ceramics with multiphase boundaries, and the correlation between the amount of non‐180° domain and strain is established, revealing that the mechanisms of interfacial stresses facilitate reversible domain switching during the periodic orthogonal poling. Owing to the self‐generated interfacial stresses between the adjacent regions with different poling directions, an enhanced strain benefits from non‐180° domain switching, which is reversible during periodic orthogonal poling. The enhancement in strain decreases from O‐T to R‐O‐T to the R‐T phase boundary, which corresponds to the different quantity of the non‐180° domain, indicating that a large amount of non‐180° domains can further boost high strain under periodic orthogonal poling. Notably, a slight frequency‐dependent strain was observed across the frequency range of 1‒50 Hz. Therefore, an ideal strain can be further induced by enhancing the amount of reversible non‐180° domain switching in the multiphase boundary during periodic orthogonal poling, which can serve as a guide for the design of high‐performance KNN materials.

Temperature Drift Characteristics Analysis of GMM-FBG Current Sensor Based on Finite-Element Multi-Physics Simulations

A composite current sensor is designed with soft ferrite as the magnetizer in combination with giant magnetostrictive material (GMM) and fiber Bragg grating (FBG). The temperature drift characteristics of the GMM, detecting performances under thermal strain caused by temperature variation in the GMM rod, are investigated by simulating the coupled fields of magnetostriction and thermal expansion with the finite-element multi-physics method to explore the temperature-drift mechanism of the ferrite–GMM current detector. The sensing characteristics of the GMM-FBG current sensor under quasi-static current excitation at various work temperatures are evaluated by simulating thermal stress between the GMM and FBG to analyze the temperature drift mechanism of the Bragg wavelength signal modulated by FBG. Even though temperature elevation suppresses GMM magnetization and thereby reduces the slopes of stress–strain curves, the steering magnetization of magnetic domains in the GMM rod tends to saturation without appreciable thermal inhibition in the high-stress region of large current excitation, while the magnetostrictive strain is still abated by the reduction in magnetic flux density caused by the thermal expansion of GMM rods. The temperature elevation can also produce thermal stress between the GMM and FBG, which will decrease the detection sensitivity and testing range of the GMM-FBG current sensor. The temperature drift characteristics of the GMM-FBG are generalized into a formula by fitting the wavelength shifting as a function of thermal strain, which will significantly facilitate designing the scale calibration for various ambient temperatures. The present researchers provide a theoretical basis and experimental guidance for developing GMM-FBG current sensors with high sensitivity and stability.

Choosing the best magnetostrictive material for energy harvesting applications: A simple criterion based on Ericsson cycles

The best magnetostrictive material for energy harvesting applications is not necessarily the material with the highest magnetostriction strain. In this paper, based on the description of the Ericsson cycle, a simple criterion to define the most efficient material is proposed. The criterion takes into account the accessible range of stress and magnetic field. It relies on four material parameters only, namely the initial magnetic susceptibility, the saturation magnetisation, the maximum magnetostriction strain and the coercive field of the considered magnetostrictive material. Mass density and price are also involved if a weight optimisation or a cost optimisation is sought. The potential of several materials is compared based on this approach, and it is shown that Giant Magnetostrictive Materials are not systematically the best choice for energy harvesting applications, challenged for some operating conditions by electrical steels.

Estimation of iron losses in Terfenol-D for variable DC-biased and AC excitation conditions

Giant magnetostrictive material (GMM) is well known for its hysteresis behaviors related to multiple influencing factors, such as bias magnetic field and excitation level. This feature greatly challenges the loss prediction of giant magnetostrictive transducers. The existing loss prediction models need further improvement to cover the sensitive magnetic properties of GMM. In this paper, the variations of the iron losses with the operation conditions are interpreted by the variations of the Jiles–Atherton model parameters, and a concise parameter identification procedure with great generalizability is proposed. The iron losses of Terfenol-D under variable excitation levels and the DC biases are further investigated. With the proposed procedure, the introduced eight additional modification parameters for the original Jiles–Atherton model are easy to obtain, and merely a few hysteresis loops of Terfenol-D are involved. An experimental setup is established for further demonstration. Comparisons between the measured and calculated results indicate the effectiveness of the proposed approach. Throughout the bias-excitation space within the frequency range under investigation, the iron losses can be precisely estimated with an acceptable error of less than 5%.

Simultaneous magnetic field and temperature measurement with high resolution based on cascaded microwave photonic filters.

A simultaneous magnetic field and temperature sensing scheme based on cascaded microwave photonic filters (MPFs) with high resolution is proposed and experimentally demonstrated. A polarization maintaining fiber bonded with a giant magnetostrictive material acts both as a magnetic field sensing probe and an important unit of a dispersion-induced MPF. A 500 m single mode fiber in a two-tap MPF is used to perform temperature compensation. The power fading frequency of the dispersion-induced MPF and the dip frequency of the two-tap MPF are selected to monitor the magnetic field and temperature changes. When temperature changes, both power fading frequency and dip frequency will change. While only power fading frequency shifts as magnetic field changes. Consequently, dual parameter sensing can be achieved by monitoring the characteristic microwave frequencies of the two MPFs. The temperature cross-sensitivity is well resolved in this way. In the experiment, the microwave frequency changes 5.84 MHz as external magnetic field increases by 1 mT. The corresponded theoretical resolution can reach 0.17 nT, which is only limited by the minimum resolution of vector network analyzer.

Loss-based structures and frequency dependencies of giant magnetostrictive materials for rotary ultrasonic machining applications

Loss-based structures and frequency dependencies of giant magnetostrictive materials for rotary ultrasonic machining applications

Modeling the dynamic behavior of manipulator joint based on giant magnetostrictive material.

The existing space manipulator joints with permanent magnet synchronous motors (PMSMs) have many deficiencies, such as large size, low output torque, and long settling time. In this paper, the dynamic behavior of space manipulators with smart giant magnetostrictive material (GMM) joints is studied. A nonlinear dynamic model considering the magneto-thermal-mechanical coupling for the manipulator is established, and an experiment is conducted to evaluate the performance of the GMM joint. After verifying the accuracy and availability of the model, we find that comparing with the PMSM joint, manipulators with the GMM joint have better performance, which has large output torque, fast settling time, and wide temperature adaptation range. These essential investigations will be of significant benefit to the applications in space manipulators.

Anti-plane dynamics of right-angle rare earth giant magnetostrictive medium with cylindrical conducting inclusion

In this paper, the anti-plane dynamics of rare earth giant magnetostrictive material with a cylindrical magnetically conducting inclusion in right-angle domain under the incidence of SH waves are studied. The governing equation and constitutive equation of magneto-elastic coupling are established. The outward scattered wave and internal standing wave caused by the inclusion are given by combining the complex function method, the wave function expansion method and mirror method. At the same time, the magnetic potential caused by wave is given by solving the Laplace equation. On the basis of boundary conditions, the Fourier series expansion method and effective truncated series are introduced to establish and solve infinite linear algebraic integral equations. Finally, based on numerical calculation, the analysis of dynamic stress concentration factor and magnetic field intensity concentration factor under different parameter combinations is given. The purpose of this paper is to provide an effective analytical method for the research of fracture dynamics of giant magnetostrictive materials under multi-magnetic field coupling.

Development of an ANC System with a Giant Magnetostrictive Actuator for Ultra-Compact Electric Vehicles: Thrust Force Characteristics Including Road Noise Range

Ultra-compact electric vehicles (EVs) have been recently sold as next-generation vehicles. However, they are yet to reach a notable phase of expansion and use. Ultra-compact EVs have compact and lightweight bodies. As the outer plate of an ultra-compact EV has low rigidity, the road noise generated by the tires and the wind noise generated from the vehicle’s projection shape are transmitted to the interior of the vehicle. Therefore, a new active noise control (ANC) system with a giant magnetostrictive actuator for ultra-compact EVs has been recently proposed. The giant magnetostrictive actuator is required to produce sufficient thrust, with less distortion, and delayed sound waves. In this work, we studied the thrust force characteristics of the giant magnetostrictive material, including in the road noise range. We considered the giant magnetostrictive thrust for output, including in the road noise range, using a finite element model of the giant magnetostrictive actuator by conducting an electromagnetic field analysis. The results showed that the effect of the thrust on the frequency changes depending on the length of the giant magnetostrictive material.

The magneto-mechanic hysteresis model for giant magnetostrictive materials based on the magnetic domain theory

In the paper, a magneto-mechanic hysteresis model for giant magnetostrictive materials is suggested by considering the effect of the domain rotation and domain wall motion on the magnetization process under prestress and the applied magnetic field. The coercive force, which is magneto-mechanic dependent, is proposed instead of a pinning constant in the Jiles–Atherton model. The model can well predict the characteristics of a magnetization-applied field curve and magnetostrictive strain-applied field curve shown in the experiment, especially the “overturn phenomenon” under different compressive prestresses. Furthermore, the effect of the microstructure parameter, such as the ratio of the domain wall thickness to the internal stress wavelength, the amplitude of internal stress, the ratio of the domain wall thickness to the inclusion radius, and inclusion consistency, on coercive force under applied prestress can also be described by the model. The comparison between the results predicted by the model and experiment shows that the model is suited for a wide-ranging applied magnetic field.