Magnetostrictive effects and magnetocrystalline anisotropy are fundamental physical properties governing magnon dynamics in magnetic systems. Recent evidence shows that strain-mediated magnetostrictive coupling provid...Magnetostrictive effects and magnetocrystalline anisotropy are fundamental physical properties governing magnon dynamics in magnetic systems. Recent evidence shows that strain-mediated magnetostrictive coupling provides an effective pathway for modulating magnonic excitation through quantum interference. Nevertheless, the microscopic origins of magnetocrystalline anisotropy in manipulating magnon excitation pathways, particularly regarding magnonic Kerr nonlinearity and crystal direction constraints, require further investigation. In this study, we construct a dual-frequency driven magnomechanical model based on yttrium iron garnet(YIG) spheres. By introducing a Hamiltonian with the magnonic Kerr nonlinear term, we combine the Heisenberg–Langevin equations and the mean field approximation to analytically solve for the driving efficiency η, and we base our analysis on experimental parameters to evaluate the impacts of the magnonic Kerr coefficient(K), driving field(B_1) and YIG size. The results show that the magnetocrystalline anisotropy induces a MHz-scale frequency shift, splitting the transmission spectrum from a Lorentzian line shape into asymmetric Fano resonance double peaks. The orientation of the external magnetic field(aligned with the [100] or [110] crystallographic axis) allows precise control over the sign of the magnonic Kerr coefficient K, thereby enabling a reversal in the direction of the frequency shift. A strong driving field B_1 not only enables controllable switching of the state but also adjusts the switching bandwidth. Furthermore, we show the transition of the dynamical response mechanism of the excitation efficiency spectrum with varying YIG sphere sizes. The study shows the dynamic control mechanism of the magnetocrystalline anisotropy on magnon switching and provides a theoretical foundation for size optimization and nonlinear energy manipulation in spintronic device design.展开更多
Magnetostriction materials are a significant kind of magnetic functional materials,while RFe_(2)(R=rare earth)compounds,especially Tb_(0.27)Dy_(0.73)Fe_(2),with cubic Laves phase structure,are the most famous.In this ...Magnetostriction materials are a significant kind of magnetic functional materials,while RFe_(2)(R=rare earth)compounds,especially Tb_(0.27)Dy_(0.73)Fe_(2),with cubic Laves phase structure,are the most famous.In this work,polycrystalline Pr_(x)(Tb_(0.27)Dy_(0.73))_(1-x)Fe_(1.95)(x=0,0.05,0.10,0.15,0.2,0.25)alloys were synthesized to explore the influence of adding Pr on the structural,magnetic and magnetostrictive properties of Tb_(0.27)Dy_(0.73)Fe_(1.95).The results show that Pr_(x)(Tb_(0.27)Dy_(0.73))_(1-x)Fe_(1.95)alloys can form the C15 Laves phase when x≤0.2,Meanwhile,the samples with a Pr content of up to 0.1 exhibit a higher saturation magnetostriction compared to the Pr-free sample.As the content of Pr in Pr_(x)(Tb_(0.27)Dy_(0.73))_(1-x)Fe_(1.95)rises from 0 to 0.1,the saturation magnetostriction,λs,improves from 1057 ppm to 1147 ppm.The apparent enhancement of the magnetostrictive property of Tb_(0.27)Dy_(0.73)Fe_(1.95)reveals the great potential of(Pr,Tb,Dy)Fe_(2)to become a widely-used magnetostriction material.Larger lattice distortion of the material itself leads to an increase in magnetostriction.展开更多
Excellent magnetostrictive properties and processability are the two most important key factors for the practical application of magnetostrictive materials and research directions of continuous concern.In this study,w...Excellent magnetostrictive properties and processability are the two most important key factors for the practical application of magnetostrictive materials and research directions of continuous concern.In this study,we significantly improved the magnetostriction,ductility,and tensile strength of Fe_(83)Ga_(17)B_(x)(x=0,1,2,3,and 4)alloys by adjusting the small-radius boron(B)doping concentration.When x=3,the maximum magnetostriction value reached 193 ppm,approximately twice that of the undoped alloy(x=0),while the ultimate tensile strength and elongation increased by 147%and 238%,respectively,compared to Fe_(83)Ga_(17)alloys.Both first-principles calculations and experimental results indicate that B doping facilitates the alignment of FeGa crystal growth direction with the easy magnetization axis,thereby significantly improving the magnetostrictive properties of the alloy.Additionally,increasing B content progressively refines the grain size and promotes Fe_(2)B phase formation,thereby enhancing both strength and toughness.At x=3,the material exhibits the highest saturation magnetization and the lowest coercivity.Therefore,the results show that doping small-radius atoms in the interstitial sites can effectively enhance the magnetostrictive and mechanical properties of FeGa materials.This work offers a promising strategy for designing magnetostrictive materials with superior overall properties.展开更多
A general nonlinear constitutive model is proposed for magnetostrictive materials, based on the important physical fact that a nonlinear part of the elastic strain produced by a pre-stress is related to the magnetic d...A general nonlinear constitutive model is proposed for magnetostrictive materials, based on the important physical fact that a nonlinear part of the elastic strain produced by a pre-stress is related to the magnetic domain rotation or movement and is responsible for the change of the maximum magnetostrictive strain with the pre-stress. To avoid the complicity of determining the tensor function describing the nonlinear elastic strain part, this paper proposes a simplified model by means of linearizing the nonlinear function. For the convenience of engineering applications, the expressions of the 3-D （bulk）, 2-D （film） and 1-D （rod） models are, respectively, given for an isotropic material and their applicable ranges are also discussed. By comparison with the experimental data of a Terfenol-D rod, it is found that the proposed model can accurately predict the magnetostrictive strain curves in low, moderate and high magnetic field regions for various compressive pre-stress levels. The numerical simulation further illustrates that, for either magnetostrictive rods or thin films, the proposed model can effectively describe the effects of the pre-stress or residual stress on the magnetization and magnetostrictive strain curves, while none of the known models can capture all of them. Therefore, the proposed model enjoys higher precision and wider applicability than the previous models, especially in the region of the high field.展开更多
The mutual coupling of structure and magnetism is crucial for Heusler alloys.In this paper,Ni_(50)Mn_(34)Sb_(16-x)Ga_(x)(0≤x≤16)alloys were prepared by arc melting.Based on the test results of structure and magnetis...The mutual coupling of structure and magnetism is crucial for Heusler alloys.In this paper,Ni_(50)Mn_(34)Sb_(16-x)Ga_(x)(0≤x≤16)alloys were prepared by arc melting.Based on the test results of structure and magnetism,the magnetic-structural phase diagram of Ni_(50)Mn_(34)Sb_(16-x)Ga_(x)(0≤x≤16)was drawn.The structure changes from cubic to monoclinic and finally to tetragonal as the x increases at room temperature.Its phase diagram shows a morphotropic phase boundary(MPB)starting from a tricritical triple point(around the Ni_(50)Mn_(34)Sb_(5)Ga_(11)alloy)of a cubic paramagnetic phase,ferromagnetic monoclinic,and antiferromagnetic tetragonal phases.And Ni_(50)Mn_(34)Sb_(5)Ga_(11)alloy has experienced five different phase states:paramagnetic austenite→ferromagnetic austenite→antiferromagnetic martensite→ferromagnetic martensite→spin glass as the temperature decreased.Further study of the alloys’magnetostrictive properties near the MPB showed that as x increases,a negative strain initially appears,followed by a W-type that crosses negative and positive strains,and then a positive strain.This is caused by the inconsistency in the speed and degree of magnetic domain walls response with monoclinic and tetragonal coexisting structures.This indicates that coupling between structure and magnetism is critical to the properties of materials.This work provides valuable insights into the magnetostrictive behavior and structural evolution of Heusler alloys,particularly in the context of MPB systems,and offers guidance for the design and optimization of material properties through controlled magnetic-structural interactions.Kindly check and confirm the edit made in the title.The edit made in the title has been confirmed to be accurate.展开更多
Giant magnetostrictive actuators (GMAs) often work in a close-loop feedback system. This system needs independent sensors which may be difficult to be fixed, besides, excessive sensors may cause more unpredicted probl...Giant magnetostrictive actuators (GMAs) often work in a close-loop feedback system. This system needs independent sensors which may be difficult to be fixed, besides, excessive sensors may cause more unpredicted problems in a large system. This paper aims to develop a self-sensing GMA. An observer based on piezomagnetic equations is constructed to estimate the stress and strain of the magnetostrictive material. The observer based self-sensing approach depends on the facts that the magnetic field is controllable and that the magnetic induction is measurable. Aiming at the nonlinear hysteresis in magnetization, a hys- teresis compensation observer based on Preisach model is developed. Experiment verified the availability of the observer approach, and the hysteresis compensation observer has higher tracking precision than linear observer for dynamic force sensing.展开更多
Magnetostrictive Fe-Ga alloys have been demonstrated potentialities for numerous applications,whereas,suffering a tradeoff between large magnetostrictive strain and high sensitivity.Herein,bulk polycrystalline Fe81Ga1...Magnetostrictive Fe-Ga alloys have been demonstrated potentialities for numerous applications,whereas,suffering a tradeoff between large magnetostrictive strain and high sensitivity.Herein,bulk polycrystalline Fe81Ga19 alloys were prepared by laser-beam powder bed fusion(LPBF)and then annealed in magnetic field for manipulating the comprehensive magnetostrictive properties.Results indicate that<001>oriented grains are developed in the LPBF-prepared Fe81Ga19 alloys due to high temperature gradient.After magnetic field annealing(MFA),the magnetic domains within the alloys gradually transformed into well-arranged stripe domains,especially,flat and smooth 90°domains were established in the alloys annealed at 2600 Oe.As a result,the induced<001>orientation grains and 90°domains contributed to an improved effective magnetic anisotropy constant(57.053 kJ/m^(3)),leading to an enhanced magnetostrictive strain of 92 ppm.Moreover,the MFA-treated alloys also displayed enhanced magnetostrictive sensitivity(0.097 ppm/Oe)owing to the smooth domain structures and low dislocation densities,demonstrating a fruitful strain-sensitivity synergy.In addition,good magnetostrictive dynamic response and enhanced compressive yield strength were also observed for the prepared alloys.This work demonstrates that LPBF and MFA might be an attractive strategy to resolve the tradeoff between strain and sensitivity,providing a basis for the preparation of high-performance magnetostrictive materials.展开更多
Chaotic motion and quasi-periodic motion are two common forms of instability in the giant magnetostrictive actuator(GMA).Therefore,in the present study we intend to investigate the influences of the system damping coe...Chaotic motion and quasi-periodic motion are two common forms of instability in the giant magnetostrictive actuator(GMA).Therefore,in the present study we intend to investigate the influences of the system damping coefficient,system stiffness coefficient,disc spring cubic stiffness factor,and the excitation force and frequency on the output stability and the hysteresis vibration of the GMA.In this regard,the nonlinear piezomagnetic equation,Jiles-Atherton hysteresis model,quadratic domain rotation model,and the GMA structural dynamics are used to establish the mathematical model of the hysteresis vibration system of the GMA.Moreover,the multi-scale method and the singularity theory are used to determine the eo-dimensional two-bifurcation characteristics of the system.Then,the output response of the system is simulated to determine the variation range of each parameter when chaos is imposed.Finally,the fourth-order Runge-Kutta method is used to obtain the time domain waveform,phase portrait and Poincare mapping diagrams of the system.Subsequently,the obtained three graphs are analyzed.The obtained results show that when the system output is stable,the variation range of each parameter can be determined.Moreover,the stability interval of system damping coefficient,system stiffness coefficient,and the coefficient of the cubic stiffness term of the disc spring are obtained.Furthermore,the stability interval of the exciting force and the excitation frequency are determined.展开更多
Some of the previous theories in the electrostrictive and magnetostrictive materials and their differences are discussed in this paper. A variational principle in the general thermodynamic sense is given and the gover...Some of the previous theories in the electrostrictive and magnetostrictive materials and their differences are discussed in this paper. A variational principle in the general thermodynamic sense is given and the governing equations can be derived from this principle. Illustrational examples are given.展开更多
Performance of giant magnetostrictive material (GMM) is introduced. Principleof work, basic structure and key techniques of giant magnetostrictive actuator (GMA) are analyzed.Its dynamic models of magneto-mechanical c...Performance of giant magnetostrictive material (GMM) is introduced. Principleof work, basic structure and key techniques of giant magnetostrictive actuator (GMA) are analyzed.Its dynamic models of magneto-mechanical coupling are established. The structure and principle ofthe pneumatic servo valve and the micro pipe robot with new homemade GMM are presented. Theexperiment is carried out under typical working conditions. The experiment results show that the GMMpneumatic servo valve has wide pressure control characteristics, good linearity, and fast responsespeed. The movement principles of the GMM robot system are reliably feasible and its maximal movingspeed is about 8 mm/s. It is preferable to the driving frequency of the robot within 100 approx 300Hz.展开更多
To bear more loads for heavy truck pistons, the shape of heavy truck piston pinhole is often designed as noncylinder form. Current methods cannot meet the needs for precision machining on non-cylinder piston pinhole ...To bear more loads for heavy truck pistons, the shape of heavy truck piston pinhole is often designed as noncylinder form. Current methods cannot meet the needs for precision machining on non-cylinder piston pinhole （NCPPH）. A novel mechanism based on giant magnetostrictive materials （GMM） is presented. New models are established for the servo mechanism, GMM, and magnetizing force of the control solenoid to characterize the relationship between the control current of the solenoid and the displacement of the giant magnetostrictive actuator （GMA）. Experiments show that the novel mechanism can meet the needs to perform fine machining on NCPPH effectively.展开更多
In order to develop a highly sensitive material for nondestructive testing(NDT),(Tb_(0.3) Dy_(0.7))Fe_(1.95) thin films were deposited on FeCo substrates at room temperature by magnetron sputtering and annealed.The ma...In order to develop a highly sensitive material for nondestructive testing(NDT),(Tb_(0.3) Dy_(0.7))Fe_(1.95) thin films were deposited on FeCo substrates at room temperature by magnetron sputtering and annealed.The magnetostrictive properties and the detection efficiency of the composite films were investigated.Results demonstrate that the detection efficiency roughly shows regular consistency with the magnetostrictive strain of the TbDyFe films. Heat treatment has a great effect on the crystalline state and the magnetostrictive strain of the composite materials. The as-deposited(Tb_(0.3) Dy_(0.7))Fe_(1.95) films are amorphous, and the saturation magnetostriction(ls) is only 90 ppm. However, the nanostructured crystalline REFe2 is partially separated out in amorphous matrix after annealing at 600C for 1 h, and the ls increases to 265 ppm. Simultaneously, the detection efficiency of the composite materials is obviously improved compared to that of the as-deposited films. The detection signal of traditional FeCo strip is0.4 V at the excitation power of 1.0 P and frequency of 128 kHz and that of the strip increases significantly by depositing one layer of(Tb_(0.3) Dy_(0.7))Fe_(1.95) film. The detection signal of the composite material annealed at 600C is the best, even reaching saturation value of 2.5 V(1.0 P, 128 kHz). The results may provide us with a method for preparing new materials for NDT.展开更多
The main attention of this paper was devoted to the study of the effect of different cooling rates on the magnetic domain configuration and magnetostrictive behavior of heat-treated Fe-15 at% Ga alloy. After annealing...The main attention of this paper was devoted to the study of the effect of different cooling rates on the magnetic domain configuration and magnetostrictive behavior of heat-treated Fe-15 at% Ga alloy. After annealing at 1,000℃ for 3 h, the samples were subjected to water quenching, air cooling, and furnace cooling treatments. Phase constitution and magnetic domain structures of the samples were studied using X-ray diffraction （XRD） and magnetic force microscopy （MFM）. XRD results indicate a single phase of α-Fe with disordered bcc （A2） structure for all samples. MFM results show that both water-quenched （WQ） and air-cooled （AC） samples are mainly made from ordered stripe domain structures, whereas a mixture of irregular stripe, zigzag, and plate domain patterns are observed in furnace-cooled （FC） sample. Magnetostrictive strain was measured in the presence of an extemally applied magnetic field. It is found that WQ sample has the highest magnetostriction, while AC and FC samples exhibit moderate and the lowest magnetostriction, respectively, against the applied field. The dependence of initial domain configurations on thermal history is found to be conducive to the change in saturation magnetostrictions of the samples.展开更多
This paper presents two numerical realization of Preisach model by Density Function Method (DFM) and F Function Method (FFM) for a giant magnetostrictive actuator (GMA). Experiment and simulation showed that FFM is be...This paper presents two numerical realization of Preisach model by Density Function Method (DFM) and F Function Method (FFM) for a giant magnetostrictive actuator (GMA). Experiment and simulation showed that FFM is better than DFM for predicting precision of hysteresis loops. Lagrange bilinear interpolation algorithm is used in Preisach numerical realization to enhance prediction performance. A set of hysteresis loops and higher order reversal curves are predicted and experimentally verified. The good agreement between the measured and predicted curves shows that the classical Preisach model is effective for modelling the quasi-static hysteresis of the GMA.展开更多
The development of the giant magnetostrictive rare earth-iron materials is reported from their discovery in the early 1970's to their present use in transducer and sensor applications. Fifteen broad market areas,...The development of the giant magnetostrictive rare earth-iron materials is reported from their discovery in the early 1970's to their present use in transducer and sensor applications. Fifteen broad market areas, ranging from miniature devices in the medical industry to high powder sonar and seismic sources have been identified. A world-wide customer base in these high technology fields has been established and the superior properties of these materials are responsible for the rapid growth of the magnetostrictive transducer industries. The critical design criteria that lead to efficient devices are reported and the performance of several of these products is presented. The key patents associated with these giant magnetostrictive materials and devices using these materials are reviewed. The present and future of these technologies in reference to commercialization, market growth and the impact on the many transduction industries are discussed. (Author abstract) 9 Refs.展开更多
In this paper, a nonlinear and coupled constitutive model for giant magnetostrictive materials （GMM） is employed to predict the active vibration suppression process of cantilever laminated composite plate with GMM l...In this paper, a nonlinear and coupled constitutive model for giant magnetostrictive materials （GMM） is employed to predict the active vibration suppression process of cantilever laminated composite plate with GMM layers. The nonlinear and coupled constitutive model has great advantages in demonstrating the inherent and complicated nonlinearities of GMM in re- sponse to applied magnetic field under variable bias conditions （pre-stress and bias magnetic field）. The Hamilton principle is used to derive the nonlinear and coupled governing differential equation for a cantilever laminated composite plate with GMM layers. The derived equation is handled by the finite element method （FEM） in space domain, and solved with Newmark method and an iteration process in time domain. The numerical simulation results indicate that the proposed active control system by embedding GMM layers in cantilever laminated composite plate can efficiently suppress vibrations under variable bias conditions. The effects of embedded placement of GMM layers and control gain on vibration suppression are discussed respectively in detail.展开更多
An infinite panel model of giant magnetostrictive material loudspeaker system （GMMLS） is proposed by making use of finite element method（FEM）. Bending wave eigenfunction is introduced to describe the acoustic radi...An infinite panel model of giant magnetostrictive material loudspeaker system （GMMLS） is proposed by making use of finite element method（FEM）. Bending wave eigenfunction is introduced to describe the acoustic radiation condition of the panel. Far-field response in different conditions is calculated by changing the mass surface density. Conclusion is obtained by analyzing the curves simulated, that panel which has larger mass surface density can hardly generate far-field acoustic radiation for lower frequency, while the panel has smaller mass surface density generates far-field acoustic radiation for lower frequency evenly and stronger.展开更多
The nonlinear dynamic characteristics and optimal control of a giant magnetostrictive film （GMF）-shaped memory alloy （SMA） composite plate subjected to in-plane stochastic excitation are studied. GMF is prepared b...The nonlinear dynamic characteristics and optimal control of a giant magnetostrictive film （GMF）-shaped memory alloy （SMA） composite plate subjected to in-plane stochastic excitation are studied. GMF is prepared based on an SMA plate, and combined into a GMF-SMA composite plate. The Van der Pol item is improved to explain the hysteretic phenomena of GMF and SMA, and the nonlinear dynamics model of a GMF-SMA composite cantilever plate subjected to in-plane stochastic excitation is developed. The stochastic stability of the system is analyzed, and the steady-state probability density function of the dynamic response of the system is obtained. The condition of stochastic Hopf bifurcation is discussed, the reliability function of the system is provided, and then the probability density of the first-passage time is given. Finally, the stochastic optimal control strategy is proposed by the stochastic dynamic programming method. Numerical simulation shows that the stability of the trivial solution varies with bifurcation parameters, and stochastic Hopf bifurcation appears in the process; the system＇s reliability is improved through stochastic optimal control, and the first- passage time is delayed. A GMF-SMA composite plate combines the advantages of GMF and SMA, and can reduce vibration through passive control and active control effectively. The results are helpful for the engineering applications of GMF-SMA composite plates.展开更多
Rare earth giant magnetostrictive materials(GMMs)Tb_(1-x)Dy_(x)Fe_(2±δ)(Tb-Dy-Fe)have been successfully employed in many microelectromechanical devices due to their excellent magnetostrictive properties at room ...Rare earth giant magnetostrictive materials(GMMs)Tb_(1-x)Dy_(x)Fe_(2±δ)(Tb-Dy-Fe)have been successfully employed in many microelectromechanical devices due to their excellent magnetostrictive properties at room temperature.However,Tb-Dy-Fe still shows a relatively large coercivity with high hysteresis,which inevitably limits its application range.Herein,micromagnetic simulations are performed to investigate the size effect of precipitated phase(α-Fe)on coercivity in Tb-Dy-Fe.Simulation results demonstrate that the coercivity is reduced from 31.46 to 12.48 mT with increasing the size ofα-Fe from 4 to 50 nm in Tb-Dy-Fe since the precipitated phase ofα-Fe can act as a magnetization reversal nucleus.This decreasing trend of coercivity can be well fitted with an inverse square relationship,which agrees well with the nucleation theory.Our study highlights that the coercivity of Tb-Dy-Fe can be tailored by tuning the size ofα-Fe precipitation.展开更多
This study presents a new method to solve the difficult problem of precise machining a non-cylinder pinhole of a piston using embedded giant magnetostrictive material (GMM) in the component. We propose the finite elem...This study presents a new method to solve the difficult problem of precise machining a non-cylinder pinhole of a piston using embedded giant magnetostrictive material (GMM) in the component. We propose the finite element model of GMM smart component in electric, magnetic, and mechanical fields by step computation to optimize the design of GMM smart com-ponent. The proposed model is implemented by using COMSOL multi-physics V3.2a. The effects of the smart component on the deformation and the system resonance frequencies are studied. The results calculated by the model are in excellent agreement (relative errors are below 10%) with the experimental values.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12022507 and 11774113)。
文摘Magnetostrictive effects and magnetocrystalline anisotropy are fundamental physical properties governing magnon dynamics in magnetic systems. Recent evidence shows that strain-mediated magnetostrictive coupling provides an effective pathway for modulating magnonic excitation through quantum interference. Nevertheless, the microscopic origins of magnetocrystalline anisotropy in manipulating magnon excitation pathways, particularly regarding magnonic Kerr nonlinearity and crystal direction constraints, require further investigation. In this study, we construct a dual-frequency driven magnomechanical model based on yttrium iron garnet(YIG) spheres. By introducing a Hamiltonian with the magnonic Kerr nonlinear term, we combine the Heisenberg–Langevin equations and the mean field approximation to analytically solve for the driving efficiency η, and we base our analysis on experimental parameters to evaluate the impacts of the magnonic Kerr coefficient(K), driving field(B_1) and YIG size. The results show that the magnetocrystalline anisotropy induces a MHz-scale frequency shift, splitting the transmission spectrum from a Lorentzian line shape into asymmetric Fano resonance double peaks. The orientation of the external magnetic field(aligned with the [100] or [110] crystallographic axis) allows precise control over the sign of the magnonic Kerr coefficient K, thereby enabling a reversal in the direction of the frequency shift. A strong driving field B_1 not only enables controllable switching of the state but also adjusts the switching bandwidth. Furthermore, we show the transition of the dynamical response mechanism of the excitation efficiency spectrum with varying YIG sphere sizes. The study shows the dynamic control mechanism of the magnetocrystalline anisotropy on magnon switching and provides a theoretical foundation for size optimization and nonlinear energy manipulation in spintronic device design.
基金supported by a grant from the Research Projects of Ganjiang Innovation Academy,Chinese Academy of Sciences(E355B003)。
文摘Magnetostriction materials are a significant kind of magnetic functional materials,while RFe_(2)(R=rare earth)compounds,especially Tb_(0.27)Dy_(0.73)Fe_(2),with cubic Laves phase structure,are the most famous.In this work,polycrystalline Pr_(x)(Tb_(0.27)Dy_(0.73))_(1-x)Fe_(1.95)(x=0,0.05,0.10,0.15,0.2,0.25)alloys were synthesized to explore the influence of adding Pr on the structural,magnetic and magnetostrictive properties of Tb_(0.27)Dy_(0.73)Fe_(1.95).The results show that Pr_(x)(Tb_(0.27)Dy_(0.73))_(1-x)Fe_(1.95)alloys can form the C15 Laves phase when x≤0.2,Meanwhile,the samples with a Pr content of up to 0.1 exhibit a higher saturation magnetostriction compared to the Pr-free sample.As the content of Pr in Pr_(x)(Tb_(0.27)Dy_(0.73))_(1-x)Fe_(1.95)rises from 0 to 0.1,the saturation magnetostriction,λs,improves from 1057 ppm to 1147 ppm.The apparent enhancement of the magnetostrictive property of Tb_(0.27)Dy_(0.73)Fe_(1.95)reveals the great potential of(Pr,Tb,Dy)Fe_(2)to become a widely-used magnetostriction material.Larger lattice distortion of the material itself leads to an increase in magnetostriction.
基金financially supported by Shaanxi Provincial Key Laboratory Open Project(No.2022ZY2JCY1-01-05)the National Key Research and Development Program of China(No.2021YFB3501401)+3 种基金the National Natural Science Foundation of China(Nos.52171190 and 52301250)the Key Scientific and Technological Innovation Team of Shaanxi Province(No.2020TD001)the Innovation Capability Support Program of Shaanxi(Nos.2018PT-28 and 2017KTPT-04)the support from the High Performance Computing Center at Xi'an Jiaotong University
文摘Excellent magnetostrictive properties and processability are the two most important key factors for the practical application of magnetostrictive materials and research directions of continuous concern.In this study,we significantly improved the magnetostriction,ductility,and tensile strength of Fe_(83)Ga_(17)B_(x)(x=0,1,2,3,and 4)alloys by adjusting the small-radius boron(B)doping concentration.When x=3,the maximum magnetostriction value reached 193 ppm,approximately twice that of the undoped alloy(x=0),while the ultimate tensile strength and elongation increased by 147%and 238%,respectively,compared to Fe_(83)Ga_(17)alloys.Both first-principles calculations and experimental results indicate that B doping facilitates the alignment of FeGa crystal growth direction with the easy magnetization axis,thereby significantly improving the magnetostrictive properties of the alloy.Additionally,increasing B content progressively refines the grain size and promotes Fe_(2)B phase formation,thereby enhancing both strength and toughness.At x=3,the material exhibits the highest saturation magnetization and the lowest coercivity.Therefore,the results show that doping small-radius atoms in the interstitial sites can effectively enhance the magnetostrictive and mechanical properties of FeGa materials.This work offers a promising strategy for designing magnetostrictive materials with superior overall properties.
基金The project supported by the National Natural Science Foundation of China(10132010 and 90405005 )
文摘A general nonlinear constitutive model is proposed for magnetostrictive materials, based on the important physical fact that a nonlinear part of the elastic strain produced by a pre-stress is related to the magnetic domain rotation or movement and is responsible for the change of the maximum magnetostrictive strain with the pre-stress. To avoid the complicity of determining the tensor function describing the nonlinear elastic strain part, this paper proposes a simplified model by means of linearizing the nonlinear function. For the convenience of engineering applications, the expressions of the 3-D （bulk）, 2-D （film） and 1-D （rod） models are, respectively, given for an isotropic material and their applicable ranges are also discussed. By comparison with the experimental data of a Terfenol-D rod, it is found that the proposed model can accurately predict the magnetostrictive strain curves in low, moderate and high magnetic field regions for various compressive pre-stress levels. The numerical simulation further illustrates that, for either magnetostrictive rods or thin films, the proposed model can effectively describe the effects of the pre-stress or residual stress on the magnetization and magnetostrictive strain curves, while none of the known models can capture all of them. Therefore, the proposed model enjoys higher precision and wider applicability than the previous models, especially in the region of the high field.
基金supported by the National Key Research and Development Program of China(Nos.2022YFE0109500 and 2021YFB3501401)the National Natural Science Foundation of China(Nos.52171190 and 52301250).
文摘The mutual coupling of structure and magnetism is crucial for Heusler alloys.In this paper,Ni_(50)Mn_(34)Sb_(16-x)Ga_(x)(0≤x≤16)alloys were prepared by arc melting.Based on the test results of structure and magnetism,the magnetic-structural phase diagram of Ni_(50)Mn_(34)Sb_(16-x)Ga_(x)(0≤x≤16)was drawn.The structure changes from cubic to monoclinic and finally to tetragonal as the x increases at room temperature.Its phase diagram shows a morphotropic phase boundary(MPB)starting from a tricritical triple point(around the Ni_(50)Mn_(34)Sb_(5)Ga_(11)alloy)of a cubic paramagnetic phase,ferromagnetic monoclinic,and antiferromagnetic tetragonal phases.And Ni_(50)Mn_(34)Sb_(5)Ga_(11)alloy has experienced five different phase states:paramagnetic austenite→ferromagnetic austenite→antiferromagnetic martensite→ferromagnetic martensite→spin glass as the temperature decreased.Further study of the alloys’magnetostrictive properties near the MPB showed that as x increases,a negative strain initially appears,followed by a W-type that crosses negative and positive strains,and then a positive strain.This is caused by the inconsistency in the speed and degree of magnetic domain walls response with monoclinic and tetragonal coexisting structures.This indicates that coupling between structure and magnetism is critical to the properties of materials.This work provides valuable insights into the magnetostrictive behavior and structural evolution of Heusler alloys,particularly in the context of MPB systems,and offers guidance for the design and optimization of material properties through controlled magnetic-structural interactions.Kindly check and confirm the edit made in the title.The edit made in the title has been confirmed to be accurate.
基金Project supported by the National Natural Science Foundation ofChina (No. 50105019)the China Postdoctoral Science Foundation (No. 20060390337)
文摘Giant magnetostrictive actuators (GMAs) often work in a close-loop feedback system. This system needs independent sensors which may be difficult to be fixed, besides, excessive sensors may cause more unpredicted problems in a large system. This paper aims to develop a self-sensing GMA. An observer based on piezomagnetic equations is constructed to estimate the stress and strain of the magnetostrictive material. The observer based self-sensing approach depends on the facts that the magnetic field is controllable and that the magnetic induction is measurable. Aiming at the nonlinear hysteresis in magnetization, a hys- teresis compensation observer based on Preisach model is developed. Experiment verified the availability of the observer approach, and the hysteresis compensation observer has higher tracking precision than linear observer for dynamic force sensing.
基金supported by the following funds:The Natural Science Foundation of China(52275395,51935014,82072084)The Science and Technology Innovation Program of Hunan Province(2023RC3046)+5 种基金Young Elite Scientists Sponsorship Program by CAST(2020QNRC002)National Key Research and Development Program of China(2023YFB4605800)Central South University Innovation-Driven Research Programme(2023CXQD023)JiangXi Provincial Natural Science Foundation of China(20224ACB204013)The Project of State Key Laboratory of Precision Manufacturing for Extreme Service Performance,Central South UniversityThe Fundamental Research Funds for the Central Universities of Central South University(1053320230182).
文摘Magnetostrictive Fe-Ga alloys have been demonstrated potentialities for numerous applications,whereas,suffering a tradeoff between large magnetostrictive strain and high sensitivity.Herein,bulk polycrystalline Fe81Ga19 alloys were prepared by laser-beam powder bed fusion(LPBF)and then annealed in magnetic field for manipulating the comprehensive magnetostrictive properties.Results indicate that<001>oriented grains are developed in the LPBF-prepared Fe81Ga19 alloys due to high temperature gradient.After magnetic field annealing(MFA),the magnetic domains within the alloys gradually transformed into well-arranged stripe domains,especially,flat and smooth 90°domains were established in the alloys annealed at 2600 Oe.As a result,the induced<001>orientation grains and 90°domains contributed to an improved effective magnetic anisotropy constant(57.053 kJ/m^(3)),leading to an enhanced magnetostrictive strain of 92 ppm.Moreover,the MFA-treated alloys also displayed enhanced magnetostrictive sensitivity(0.097 ppm/Oe)owing to the smooth domain structures and low dislocation densities,demonstrating a fruitful strain-sensitivity synergy.In addition,good magnetostrictive dynamic response and enhanced compressive yield strength were also observed for the prepared alloys.This work demonstrates that LPBF and MFA might be an attractive strategy to resolve the tradeoff between strain and sensitivity,providing a basis for the preparation of high-performance magnetostrictive materials.
基金Project supported by the Science Fund from the Ministry of Science and Technology of China(Grant No.2017M010660)the Major Project of the Inner Mongolia Autonomous Region,China(Grant No.2018ZD10).
文摘Chaotic motion and quasi-periodic motion are two common forms of instability in the giant magnetostrictive actuator(GMA).Therefore,in the present study we intend to investigate the influences of the system damping coefficient,system stiffness coefficient,disc spring cubic stiffness factor,and the excitation force and frequency on the output stability and the hysteresis vibration of the GMA.In this regard,the nonlinear piezomagnetic equation,Jiles-Atherton hysteresis model,quadratic domain rotation model,and the GMA structural dynamics are used to establish the mathematical model of the hysteresis vibration system of the GMA.Moreover,the multi-scale method and the singularity theory are used to determine the eo-dimensional two-bifurcation characteristics of the system.Then,the output response of the system is simulated to determine the variation range of each parameter when chaos is imposed.Finally,the fourth-order Runge-Kutta method is used to obtain the time domain waveform,phase portrait and Poincare mapping diagrams of the system.Subsequently,the obtained three graphs are analyzed.The obtained results show that when the system output is stable,the variation range of each parameter can be determined.Moreover,the stability interval of system damping coefficient,system stiffness coefficient,and the coefficient of the cubic stiffness term of the disc spring are obtained.Furthermore,the stability interval of the exciting force and the excitation frequency are determined.
基金Project supported by the National Natural Science Foundation of China(No.10472069).
文摘Some of the previous theories in the electrostrictive and magnetostrictive materials and their differences are discussed in this paper. A variational principle in the general thermodynamic sense is given and the governing equations can be derived from this principle. Illustrational examples are given.
基金This project is supported by National Natural Science Foundation of China (No.59835160).
文摘Performance of giant magnetostrictive material (GMM) is introduced. Principleof work, basic structure and key techniques of giant magnetostrictive actuator (GMA) are analyzed.Its dynamic models of magneto-mechanical coupling are established. The structure and principle ofthe pneumatic servo valve and the micro pipe robot with new homemade GMM are presented. Theexperiment is carried out under typical working conditions. The experiment results show that the GMMpneumatic servo valve has wide pressure control characteristics, good linearity, and fast responsespeed. The movement principles of the GMM robot system are reliably feasible and its maximal movingspeed is about 8 mm/s. It is preferable to the driving frequency of the robot within 100 approx 300Hz.
基金the National High-Technology Research and Development Program of China (Grant No.2006AA03z106)
文摘To bear more loads for heavy truck pistons, the shape of heavy truck piston pinhole is often designed as noncylinder form. Current methods cannot meet the needs for precision machining on non-cylinder piston pinhole （NCPPH）. A novel mechanism based on giant magnetostrictive materials （GMM） is presented. New models are established for the servo mechanism, GMM, and magnetizing force of the control solenoid to characterize the relationship between the control current of the solenoid and the displacement of the giant magnetostrictive actuator （GMA）. Experiments show that the novel mechanism can meet the needs to perform fine machining on NCPPH effectively.
基金Project supported by the National Natural Science Foundation of China(51501016)
文摘In order to develop a highly sensitive material for nondestructive testing(NDT),(Tb_(0.3) Dy_(0.7))Fe_(1.95) thin films were deposited on FeCo substrates at room temperature by magnetron sputtering and annealed.The magnetostrictive properties and the detection efficiency of the composite films were investigated.Results demonstrate that the detection efficiency roughly shows regular consistency with the magnetostrictive strain of the TbDyFe films. Heat treatment has a great effect on the crystalline state and the magnetostrictive strain of the composite materials. The as-deposited(Tb_(0.3) Dy_(0.7))Fe_(1.95) films are amorphous, and the saturation magnetostriction(ls) is only 90 ppm. However, the nanostructured crystalline REFe2 is partially separated out in amorphous matrix after annealing at 600C for 1 h, and the ls increases to 265 ppm. Simultaneously, the detection efficiency of the composite materials is obviously improved compared to that of the as-deposited films. The detection signal of traditional FeCo strip is0.4 V at the excitation power of 1.0 P and frequency of 128 kHz and that of the strip increases significantly by depositing one layer of(Tb_(0.3) Dy_(0.7))Fe_(1.95) film. The detection signal of the composite material annealed at 600C is the best, even reaching saturation value of 2.5 V(1.0 P, 128 kHz). The results may provide us with a method for preparing new materials for NDT.
基金the support of Center of Excellence for High Performance Materials(CEPMAT)at University of Tehran for providing vacuum arc melting
文摘The main attention of this paper was devoted to the study of the effect of different cooling rates on the magnetic domain configuration and magnetostrictive behavior of heat-treated Fe-15 at% Ga alloy. After annealing at 1,000℃ for 3 h, the samples were subjected to water quenching, air cooling, and furnace cooling treatments. Phase constitution and magnetic domain structures of the samples were studied using X-ray diffraction （XRD） and magnetic force microscopy （MFM）. XRD results indicate a single phase of α-Fe with disordered bcc （A2） structure for all samples. MFM results show that both water-quenched （WQ） and air-cooled （AC） samples are mainly made from ordered stripe domain structures, whereas a mixture of irregular stripe, zigzag, and plate domain patterns are observed in furnace-cooled （FC） sample. Magnetostrictive strain was measured in the presence of an extemally applied magnetic field. It is found that WQ sample has the highest magnetostriction, while AC and FC samples exhibit moderate and the lowest magnetostriction, respectively, against the applied field. The dependence of initial domain configurations on thermal history is found to be conducive to the change in saturation magnetostrictions of the samples.
基金Project supported by the National Natural Science Foundation of China (No. 50105019)China Postdoctoral Science Foundation (No. 20060390337)
文摘This paper presents two numerical realization of Preisach model by Density Function Method (DFM) and F Function Method (FFM) for a giant magnetostrictive actuator (GMA). Experiment and simulation showed that FFM is better than DFM for predicting precision of hysteresis loops. Lagrange bilinear interpolation algorithm is used in Preisach numerical realization to enhance prediction performance. A set of hysteresis loops and higher order reversal curves are predicted and experimentally verified. The good agreement between the measured and predicted curves shows that the classical Preisach model is effective for modelling the quasi-static hysteresis of the GMA.
文摘The development of the giant magnetostrictive rare earth-iron materials is reported from their discovery in the early 1970's to their present use in transducer and sensor applications. Fifteen broad market areas, ranging from miniature devices in the medical industry to high powder sonar and seismic sources have been identified. A world-wide customer base in these high technology fields has been established and the superior properties of these materials are responsible for the rapid growth of the magnetostrictive transducer industries. The critical design criteria that lead to efficient devices are reported and the performance of several of these products is presented. The key patents associated with these giant magnetostrictive materials and devices using these materials are reviewed. The present and future of these technologies in reference to commercialization, market growth and the impact on the many transduction industries are discussed. (Author abstract) 9 Refs.
基金Project supported by the National Natural Science Foundation of China(Nos.10972094,11032006,11172285,11121202and 11202087)the Fundamental Research Funds for the Central Universities(lzujbky-2011-6)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education under Grant 20110211120027the Zhejiang Provincial Natural Science Foundation of China(No.LR13A020002)
文摘In this paper, a nonlinear and coupled constitutive model for giant magnetostrictive materials （GMM） is employed to predict the active vibration suppression process of cantilever laminated composite plate with GMM layers. The nonlinear and coupled constitutive model has great advantages in demonstrating the inherent and complicated nonlinearities of GMM in re- sponse to applied magnetic field under variable bias conditions （pre-stress and bias magnetic field）. The Hamilton principle is used to derive the nonlinear and coupled governing differential equation for a cantilever laminated composite plate with GMM layers. The derived equation is handled by the finite element method （FEM） in space domain, and solved with Newmark method and an iteration process in time domain. The numerical simulation results indicate that the proposed active control system by embedding GMM layers in cantilever laminated composite plate can efficiently suppress vibrations under variable bias conditions. The effects of embedded placement of GMM layers and control gain on vibration suppression are discussed respectively in detail.
文摘An infinite panel model of giant magnetostrictive material loudspeaker system （GMMLS） is proposed by making use of finite element method（FEM）. Bending wave eigenfunction is introduced to describe the acoustic radiation condition of the panel. Far-field response in different conditions is calculated by changing the mass surface density. Conclusion is obtained by analyzing the curves simulated, that panel which has larger mass surface density can hardly generate far-field acoustic radiation for lower frequency, while the panel has smaller mass surface density generates far-field acoustic radiation for lower frequency evenly and stronger.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11272229 and 11302144)the Ph.D.Programs Foundation of the Ministry of Education of China(Grant No.20120032120006)the Tianjin Research Program of Application Foundation and Advanced Technology,China(Grant No.13JCYBJC17900)
文摘The nonlinear dynamic characteristics and optimal control of a giant magnetostrictive film （GMF）-shaped memory alloy （SMA） composite plate subjected to in-plane stochastic excitation are studied. GMF is prepared based on an SMA plate, and combined into a GMF-SMA composite plate. The Van der Pol item is improved to explain the hysteretic phenomena of GMF and SMA, and the nonlinear dynamics model of a GMF-SMA composite cantilever plate subjected to in-plane stochastic excitation is developed. The stochastic stability of the system is analyzed, and the steady-state probability density function of the dynamic response of the system is obtained. The condition of stochastic Hopf bifurcation is discussed, the reliability function of the system is provided, and then the probability density of the first-passage time is given. Finally, the stochastic optimal control strategy is proposed by the stochastic dynamic programming method. Numerical simulation shows that the stability of the trivial solution varies with bifurcation parameters, and stochastic Hopf bifurcation appears in the process; the system＇s reliability is improved through stochastic optimal control, and the first- passage time is delayed. A GMF-SMA composite plate combines the advantages of GMF and SMA, and can reduce vibration through passive control and active control effectively. The results are helpful for the engineering applications of GMF-SMA composite plates.
基金financially supported by the National Key R&D Program of China(No.2021YFB3501401)the National Natural Science Foundation of China(No.52001103)+1 种基金Zhejiang Provincial Natural Science Foundation of China(No.LQ21E010001)the Ten Thousand Talents Plan of Zhejiang Province of China(No.2019R52014)。
文摘Rare earth giant magnetostrictive materials(GMMs)Tb_(1-x)Dy_(x)Fe_(2±δ)(Tb-Dy-Fe)have been successfully employed in many microelectromechanical devices due to their excellent magnetostrictive properties at room temperature.However,Tb-Dy-Fe still shows a relatively large coercivity with high hysteresis,which inevitably limits its application range.Herein,micromagnetic simulations are performed to investigate the size effect of precipitated phase(α-Fe)on coercivity in Tb-Dy-Fe.Simulation results demonstrate that the coercivity is reduced from 31.46 to 12.48 mT with increasing the size ofα-Fe from 4 to 50 nm in Tb-Dy-Fe since the precipitated phase ofα-Fe can act as a magnetization reversal nucleus.This decreasing trend of coercivity can be well fitted with an inverse square relationship,which agrees well with the nucleation theory.Our study highlights that the coercivity of Tb-Dy-Fe can be tailored by tuning the size ofα-Fe precipitation.
基金supported by the National Natural Science Foundation of China (No. 50575205)the Hi-Tech Research and Development (863) Program of China (Nos. 2006AA04Z233 and 2007AA04Z101)+1 种基金the Doctoral Foundation of Ministry of Education of China (No. 20070335204)the Zhejiang Provincial Natural Science Foundation of China (No. Z1080537)
文摘This study presents a new method to solve the difficult problem of precise machining a non-cylinder pinhole of a piston using embedded giant magnetostrictive material (GMM) in the component. We propose the finite element model of GMM smart component in electric, magnetic, and mechanical fields by step computation to optimize the design of GMM smart com-ponent. The proposed model is implemented by using COMSOL multi-physics V3.2a. The effects of the smart component on the deformation and the system resonance frequencies are studied. The results calculated by the model are in excellent agreement (relative errors are below 10%) with the experimental values.
