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XiaoYan Lu 《Journal of magnetism and magnetic materials》2010,322(15):2113-2116
Substrate thickness effects on the magnetization and magnetostriction of Terfenol-D films was studied by using a nonlinear constitutive model combined with the Timosheko elastic theory. Results show that characteristics of Terfenol-D films on compliant substrates are different from those of their bulk counterpart. Tunable properties can be obtained by adjusting the film/substrate thickness ratio. 相似文献
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Xufeng Dong Jinping Ou Xinchun Guan 《Journal of magnetism and magnetic materials》2010,322(22):3648-3652
Magnetostrictive properties have relationship with the applied orientation field during the preparation of giant magnetostrictive composites. To understand the dependence of the optimal orientation field on particle volume fraction, composites with 20%, 30% and 50% particles by volume were fabricated by distributing Terfenol-D particles in an unsaturated polyester resin under various orientation fields. Their magnetostrictive properties were tested without pre-stress at room temperature. The results indicate that as the particle volume fraction increases, the optimal orientation field increases. The main reason for this phenomenon is the packing density for the composites with higher particle volume fraction is larger than that for those with lower particle content. 相似文献
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S.Y. Li B.W. Wang L. Weng Y. Zhou Y. Sun W.M. Huang 《Journal of magnetism and magnetic materials》2008
Based on the analysis of the magnetostriction for Terfenol-D composites, Terfenol-D 2-2 magnetostrictive composites have been prepared with laminations perpendicular to [1 1 2] axes. Then one of the samples was annealed in the vacuum at 423 K for 15 min at the magnetic field of 240 kA/m, which is along the direction of laminations and vertical to the [1 1 2] axes of the specimen. The static magnetostriction λ and dynamic magnetostrictive coefficient d33 of samples were measured under the compressive stress of 0, 2, 4, 6 and 8 MPa. Effects of the compressive stress and the magnetic field heat treatment on the magnetostriction λ have been investigated. It is found that the magnetostriction of 2-2 composites can be improved under the compressive stress when the magnetic field is larger than 20 kA/m. The magnetostriction of 2-2 composites with the magnetic field heat treatment increases under compressive stress, and it can reach 1390×10−6 at the magnetic field of 200 kA/m and under the compressive stress of 4 MPa, much larger than the value of 860×10−6 without the magnetic field heat treatment. The highest magnetostriction of the 2-2 composite with the magnetic field heat treatment can reach 1530×10−6. The dynamic magnetostrictive coefficient d33 of 2-2 composites with the magnetic field heat treatment have been improved, compared with that without magnetic field heat treatment. The maximum value of d33 of the sample with magnetic field heat treatment is 71% larger than that without magnetic field heat treatment. 相似文献
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研究了Tb0.3Dy0.7Fe2合金在压磁和磁 弹性效应中的磁畴偏转和磁导率特性. 基于Stoner-Wolhfarth 模型能量极小原理, 绘制了自由能与磁畴偏转角度的关系曲线, 研究了压应力和磁场载荷作用下磁畴角度的偏转特性, 计算分析了不同载荷作用下磁畴偏转的磁导率特性, 并与实验数据进行比较论证. 研究表明,应力和磁场的作用都将使磁畴方向[111]和[111]发生角度跃迁, 直观有效地解释了材料巨磁致伸缩效应的机理; 应力和磁场作用下磁畴的偏转将使材料磁导率呈减小趋势, 其中磁场能对磁导率的影响大于应力能, 这一现象在小载荷作用下尤为明显. 实验结果表明, 磁导率的计算数据与实验数据符合得较好, 验证了计算方法的正确性. 理论分析对Terfenol-D磁畴偏转模型的完善 和磁化过程中磁滞回线的绘制非常有意义. 相似文献
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Yongmao Pei Daining Fang Faxin Li 《Journal of magnetism and magnetic materials》2009,321(18):2783-2787
The axial and transversal linear magnetostrictions (λ∥ and λ⊥) in [1 1 0] oriented polycrystalline Tb0.3Dy0.7Fe1.95 alloys were measured simultaneously under uniaxial magnetomechanical loading to get the forced volume magnetostriction (ω=λ∥+2λ⊥). Despite the almost zero ω observed in Terfenol-D single crystals, it reaches up to 1000×10−6 in polycrystalline Tb0.3Dy0.7Fe1.95 alloys near the saturation magnetic field under a stress above 50 MPa. 相似文献
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A nonlinear constitutive model for magnetostrictive materials 总被引:2,自引:0,他引:2
Xin'en Liu Xiaojing Zheng 《Acta Mechanica Sinica》2005,21(3):278-285
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.The project supported by the National Natural Science Foundation of China (10132010 and 90405005) 相似文献
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This paper addresses the development of a one-dimension model for quantifying magnetic-elastic-thermal coupling and hysteresis inherent to giant magnetostrictive materials. Firstly, the anhysteretic law is modeled by considering the Gibbs free energy function G(σ, M, T), and thermodynamic relations are used to obtain the constitutive expressions. These expressions character the effects of coupling between stress, magnetization, and temperature in the giant magnetostrictive material but hysteresis, i.e. strain and magnetic intensity described by above the constitutive expressions are single-valued function of the magnetization. And then pinning is incorporated to describe hysteresis based on Jiles–Atherton model. The model considered in the paper is demonstrated valid by comparing the predicted results with experimental data. Moreover, the model proposed in the paper is convenient to be used in engineering applications since the parameters referred to the model have definite physical mean and can all be easily determined by experiments. 相似文献
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