共查询到20条相似文献,搜索用时 15 毫秒
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《Journal of magnetism and magnetic materials》1996,159(3):L321-L323
The Curie temperatures (Tc) of metastable nanophases have been investigated in partially crystallized Fe73.5Cu1Nb3Si13.5B9 and Fe86Zr7Cu1B6 nanostructured soft magnetic alloys as a function of annealing temperature and time. It is shown that for both materials a supersaturated phase is formed which transforms only at the second stage of crystallization by dissolution of the solute elements monitored by the steep increase of Tc. 相似文献
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非晶合金通常是将熔融的金属快速冷却、通过抑制结晶而获得的原子呈长程无序排列的金属材料.由于具有这种特殊结构,铁基软磁非晶合金具有各向同性特征、很小的结构关联尺寸和磁各向异性常数,因而具有很小的矫顽力H_c,但可和晶态材料一样具有高的饱和磁感强度B_s.优异的软磁性能促进了铁基软磁非晶合金的应用研究.目前,铁基软磁非晶/纳米晶合金带材已实现大规模工业化生产和应用,成为重要的高性能软磁材料.本文回顾了软磁非晶合金的发现和发展历程,结合成分、结构、工艺对铁基非晶/纳米晶合金软磁性能的影响,介绍了相关基础研究成果和工艺技术进步对铁基软磁非晶/纳米晶合金研发和工业化应用的重要贡献.并根据结构、性能特征将铁基软磁非晶合金研发与应用分为三个阶段,指出了目前铁基软磁非晶合金研发与应用中面临的挑战和发展方向. 相似文献
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《Current Applied Physics》2018,18(4):411-416
The viscous thermal flow behavior and mechanical property of [Fe0.6Co0.15B0.2Si0.05] (100−x)Tax (x = 0, 1, 2, 3, 4, and 5) soft magnetic amorphous ribbons were studied. The characteristics of melt-spun amorphous ribbons were measured by using vibration sample magnetometer (VSM), nanoindentation, differential scanning calorimetry (DSC) and thermo-mechanical analysis (TMA) to study the effects of Ta content variation on the thermal stability, mechanical, and soft magnetic properties. We observed that the nanoindentation hardness, Young's modulus, and glass transition and crystallization temperatures were improved by the addition of Ta. Using dilatometry measurement, TMA, by heating at a constant rate under tension mode, we examined not only the glass transition and crystallization behaviors but also the possibility of coexistence of multiple amorphous phases. 相似文献
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Sensors with cores, yokes or field concentrators made of bulk magnetic material are more sensitive and stable than thin-film sensors. Non-linearity and temperature dependence of sensitivity is often suppressed by a feedback. The common problem of these sensors is remanence, cross-field sensitivity and temperature stability of offset. The long-time effort to miniaturize the fluxgates led only to a few practical designs. For flat sensors (either pcb or CMOS) the core etched from amorphous tape gives better properties then electrodeposited or sputtered core. We compare traditional miniature fluxgates using wire cores based on longitudinal fluxgate effect with sensors using transverse fluxgate effect and GMI effect. Well-designed field concentrators or yokes can improve the parameters of any magnetic sensor. The achievable stable amplification factor is 10–100. Having a means to demagnetize the field concentrator is desirable. Overview of magnetic sensors for mechanical quantities is also given with special focus on torque sensors. 相似文献
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F. Mazaleyrat Zs. Gercsi L. K. Varga M. Lcrivain 《Journal of magnetism and magnetic materials》2004,280(2-3):391-394
In ferromagnetic amorphous and nanocrystalline soft magnetic alloys the induced magnetic anisotropy plays a fundamental role in the hysteresis behavior but, due to the elongated shape, it can be measured only if KU is perpendicular to the sample long axis. In order to measure the longitudinal induced anisotropy, an original method derived from known thin layers measurement techniques was used. Hysteresis loops shifted by perpendicular bias field were recorded for this purpose. Direct measurement of the longitudinal induced anisotropy in amorphous and nanocrystalline ribbons or wire without needing sample preparation is reported for the first time. Evidence of self-induced anisotropy is brought in a Fe–Co-based nanocrystalline alloy. 相似文献
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Amorphous magnetic materials are increasingly becoming an industrial reality, with a variety of applications to electronics
and electrical engineering. Many research lines are in progress for what concerns the production techniques, the understanding
of the structure and properties of amorphous ribbons, the optimization and extension of their applications. The fast quenching
methods used to obtain amorphous materials will first be reviewed, also describing an experimental apparatus set up by the
authors for laboratory investigations of rapid solidification processes. Becauses of the non equilibrium structure of amorphous
metallic alloys, various relaxation effects are expected to occur, which may partially limit the use of these materials. Studies
of these relaxation phenomena, performed by different methods, including Mossbauer spectroscopy will also be reviewed, showing
their importance in better understanding the amorphous structure. Finally much attention will be devoted to actual applications
of amorphous magnetic materials. Emphasis will be placed on the prospective applications of amorphous ribbons characterized
by very low power losses to magnetic cores of distribution transformers, pointing to the possible advantages, but also to
the technical problems involved with the substitution of crystalline laminations with the new amorphous materials. 相似文献
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The paper reviews selected results of the extended experimental investigations of magnetic properties, time–temperature stability and workability of the soft magnetic amorphous alloys controlled by structural magnetic relaxation. Complex approach to the magnetic relaxations in multicomponent amorphous alloys is presented. The transition from magnetic after-effect to a new MAE spectrometry is illustrated on ternary amorphous CoSiB alloy. 相似文献
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A.Z. Maksymowicz 《Journal of magnetism and magnetic materials》1985,53(3):221-228
A phenomenological model of magnetoelastic effects in amorphous substances is proposed. Assuming rapid relaxation of magnetization, an effective elastic free energy is given. The model is employed to calculate ΔE effect and sound velocities for arbitrary strength of the magnetoelastic coupling. Magnetic dynamic susceptibility is calculated in the limit of a small k-vector in bulk materials. For linear samples, the susceptibility is given for longitudinal modes in a whole range of frequencies. Magnetoacoustic resonance takes place at frequencies corresponding to a standing acoustic wave when the wavelength reaches the dimensions of the sample. 相似文献
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The surface impedance tensor approach has been used to review the impedance response in a variety of amorphous and nanocrystallized
wires. An experimental study on the torsion annealing effect on the magnetoimpedance (MI) behaviour for positive and negative
magnetostriction amorphous wires of FeSiB and CoSiB compositions, respectively, has been carried out. Moreover, the influence
of the onset nanocrystallization on the MI behaviour in Finemet-type alloys, with particular attention focussed on the case
that the wires are annealed under applied torsional stress, is also presented. The analysis of the MI and torsion-impedance
(TI) effects allows us to compare the different magnetic characteristics observed in a variety of wires. Special attention
is paid to new results of the off-diagonal MI huge responses of these ferromagnetic samples, which are also a very useful
source of information on the magnetic properties of the wires. 相似文献
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A three-dimensional (3-D) magnetic property measurement system, which can control the three components of the magnetic flux density B vector and measure the magnetic field strength H vector in a cubic sample of soft magnetic material, has been developed and calibrated. This paper studies the relationship between the B and H loci in 3-D space, and the power losses features of a soft magnetic composite when the B loci are controlled to be circles with increasing magnitudes and ellipses evolving from a straight line to circle in three orthogonal planes. It is found that the B and H loci lie in the same magnetization plane, but the H loci and power losses strongly depend on the orientation, position, and process of magnetization. On the other hand, the H vector evolves into a unique locus, and the power loss approaches a unique value, respectively, when the B vector evolves into the round locus with the same magnitude from either a series of circles or ellipses. 相似文献
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Recent advances made in the area of amorphous and nanocrystalline alloys exhibiting high saturation inductions are reviewed. A new chemical composition was identified that achieves a saturation induction of 1.64 T in an iron-based amorphous alloy. This alloy, when used in electrical transformers, shows a much improved performance over the existing amorphous alloy. Nanocrystalline FeCoCuNbSiB alloys are found to have saturation induction levels reaching 1.7 T. These materials are suited for use in sensors and inductors carrying large currents. Some of these nanocrystalline alloys show a BH squareness ratio exceeding 90%, which can be utilized in pulse power devices. Recent developments in the applications of these materials are also pointed out. 相似文献
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the amorphous layers were obtained using the method of CW CO_2 laser scanning Fe-based alloy surface. The function of structure of Fe-based alloy, scanning speed, cooling method etc. for laser-formed amorphous state were discussed. A much thick amorphous layer can be made by laser scanning. 相似文献
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Synthesis of Fe-based amorphous composite coatings with low purity materials by laser cladding 总被引:2,自引:0,他引:2
Amorphous composite coatings Fe38Ni30−XSi16B14V2MX (X = 0, 1, 2) (M contains Al, Ti, Mo, and C) were prepared with low purity of raw materials by laser cladding. X-ray diffraction and transmission electron microscopy results show that the coating have an amorphous structure with a few crystalline phase on it. The amorphous phase is the primary phase. The glass forming ability as well as the microhardness of the Fe-based alloy made from low purity raw materials can be much enhanced by adding small amount of multi-components. However, the elements addition has its optimal quantity. When X is equal to 1, the microstructure of the coating contains 97.93% amorphous phase and 2.07% crystalline phase on it. As a result, the microhardness of the coating reaches maximum. With further increasing of the additions, the amorphous phase in the coating lessens instead of augment and the crystalline phase begins to accumulate, which result in the decrease of the microhardness. 相似文献
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D.N. Zhmetko A.V. MatsuraY.N. Troschenkov S.V. Seidametov 《Journal of magnetism and magnetic materials》2011,323(1):72-76
The formation and motion of two domain walls parallel to the ribbon surface are discovered during its dynamic magnetic reversal. The domain walls form near by the middle plane of a ribbon and move to its opposite main surfaces with different velocities. 相似文献
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This paper investigates the effect of warm compaction on the magnetic and electrical properties of Fe-based soft magnetic composites at operating frequencies between 0.1 and 10 kHz. The magnetic and electrical properties of samples were measured by an LCR meter and morphology of the samples was characterized by scanning electron microscopy. It was shown that the compacted sample prepared at 800 MPa and 550 °C had the lowest magnetic loss and electrical resistivity, and highest magnetic induction and effective permeability in comparison with other samples compacted at 800 MPa and room temperature, 150, 250, 350 and 450 °C. 相似文献