共查询到19条相似文献,搜索用时 109 毫秒
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研究了非晶和纳米晶Fe85Zr3.5Nb3.5B7Cu1软磁材料的抗腐蚀的能力以及腐蚀对纳米晶软磁材料性能的影响.非晶材料晶化后抗腐蚀能力降低,主要是由于纳米晶晶界的抗腐蚀性较差的原因.材料腐蚀后将会在其表面形成一层氧化层,从而导致软磁性能的降低,磁谱测量发现,腐蚀后的样品在较大磁场下磁化时具有两个弛豫过程,在低磁下只表现为一个弛豫过程. 相似文献
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采用趋近饱和定律测定了纳米晶合金环形试样有效磁各向异性常数<K>.为了对比测量的准确度,同时测试了传统的晶态坡莫合金环形试样的磁晶各向异性.结果表明,用环形试样可以完成对低矫顽力的软磁材料进行磁各向异性的测定. 相似文献
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铁基纳米晶软磁合金的研究 总被引:8,自引:0,他引:8
本文主要评述了铁基纳米晶软磁合金的晶化过程、组织结构及其与磁性能之间的关系,分析了优异磁性能的起源,并详细论述了解释其优异磁性能的各向异性模型,提出了目前在该模型上存在的问题.此外,还介绍了纳米晶软磁材料的制备方法,并在最后对纳米晶软磁材料的应用及发展趋势作了展望. 相似文献
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研究了460~580℃等温退火(30min)后纳米晶(Fe0.5 Co0.5)73.5 Cu1Mo3Si13.5B9合金高温软磁性能.结果表明,在Fe73.5Cu1Mo3Si13.5B9纳米晶合金中用Co取代部分Fe仍可形成双相纳米晶结构,并且可显著提高合金的高温特性.与Fe73.5Cu1Mo3Si13.5B9纳米晶软磁合金相比,其室温μi略有下降,但表征高温磁稳定性的居里温度明显提高,同时磁导率在高温下衰减变缓,从而拓宽了纳米晶软磁材料的高温使用范围.文中初步探讨了用Co取代部分Fe后使高温特性得到改善的机理. 相似文献
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ChunyanBAN WenqingGAO GuiyiZENG QixianBA HualinZENG 《材料科学技术学报》2003,19(3):285-286
The magnetic properties of Fe72.5 Cu1Nb2V2Si13.5B9 alloy are investigated from an amorphous to a nanocrystalline and complete crystalline state.The sample annealed at 550℃ for 0.5h shows a homogeneous nanocrystalline structure and presents excellent soft magnetic properties.When the specimens were annealed at a temperature above 600℃,the magnetic properties are obviously deteriorated because the grain size grows up,exceeding the exchange length. 相似文献
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软磁材料是一种极为重要且应用十分广泛的能源材料,近年来,随着磁性元件的日益高频化和小型化,以及节能环保的号召,开发和研究高性能软磁材料具有重要意义。本工作概述了软磁合金的发展历史,重点归纳出各类软磁合金(包括传统软磁合金、非晶/纳米晶软磁合金、高熵软磁合金)的成分、微观组织、磁性能以及应用范围,并总结出不同软磁合金的优、缺点;指出典型合金的微观组织对合金软磁性能(尤其矫顽力)具有关键性的主导作用,进而探讨了影响软磁合金矫顽力的因素及其微观机制,发现控制晶粒尺寸(或纳米粒子尺寸)是获得低矫顽力的关键,并描述了矫顽力的微观影响机制在高熵软磁合金中的发展;最后,展望了高熵软磁合金因多主元混合的成分特性带来的组织多样化,更有利于实现对合金性能的调控,并有望作为新一代高温软磁体材料。 相似文献
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Magnetic properties of materials in their nanocrystalline state have assumed significance in recent years because of their
potential applications. A number of techniques have been used to prepare nanocrystalline magnetic phases. Melt spinning, high
energy ball milling, sputtering, glassceramization and molecular beam epitaxy are some of the physical methods used so far.
Among the chemical methods, sol-gel and co-precipitation routes have been found to be convenient. Ultrafine particles of both
ferro- and ferrimagnetic systems show superparamagnetic behaviour at room temperature. Coercivity(H
c
) and maximum energy product(BH)
max
of the magnetic particles can be changed by controlling their sizes. The present paper reviews all these aspects in the case
of nanocrystalline magnetic systems — both metallic and ceramics. 相似文献
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首先采用球磨法制备了不同粒度的Ni-Mn-Ga-Co合金粉末,然后通过3D打印技术成功制备了泡沫结构的多孔Ni-Mn-Ga-Co磁性形状记忆合金。利用SEM、DSC和XRD等研究了合金的微观组织特征、物相结构、相变特性和相关的磁性行为。结果表明,球磨后经过分筛得到的不同粒径尺寸的合金粉末均为不规则形状。Ni-Mn-Ga-Co合金粉末在室温下为非调制四方马氏体结构,其特征峰十分明显。Ni-Mn-Ga-Co合金的DSC曲线上出现宽峰相变,添加Co元素对马氏体转变温度开始值(Ms)基本没有影响,但其居里温度(Tc)有显著的提高。采用粒径为50~100μm的合金粉末烧结制备的磁性合金,饱和磁化强度最大可达68 Am^2/kg。合金粉末粒径越小,烧结制备的多孔Ni-Mn-Ga-Co磁性形状记忆合金致密度越高。当合金粉末粒径<50μm时,致密度可达90%;当合金粉末粒径为50~100μm时,致密度仅为75%。相较于粒径较小的合金粉末,粒径较大的合金粉末制备的磁性合金磁感生应变能力更高,这是由于泡沫结构能够有效减少内部和外部的约束,从而有利于提高磁场诱导应变。 相似文献
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采用粉末挤出成型法制备了FeSiAl/Fe-CuNbSiB纳米晶磁粉芯,并讨论了FeSiAl粉复合量、粉胶质量比对磁粉芯磁性能的影响。结果表明粘结剂配方为硬脂酸1%、聚丙烯20%、石蜡79%,挤出成型粉胶质量比10∶1的FeSiAl/FeCuNbSiB纳米晶磁粉芯,磁粉芯密度达到4.69g/cm3。200目FeSiAl粉与300目FeCuNbSiB纳米晶粉复合,当磁粉芯磁粉质量配比为"200目FeSiAl粉30%+300目FeCuNbSiB纳米晶粉70%"、粉胶质量比为10∶1、44℃×0.5h石油醚脱脂、热处理温度160℃×1h时,磁粉芯取得最佳的软磁性能,磁粉芯中心频率f为600kHz,有效磁导率μe达到16.48,品质因数Q值为57.5;频率及温度的变化对磁粉芯的有效磁导率的影响小。 相似文献
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《Advanced Powder Technology》2022,33(11):103823
In this work, transverse magnetic field annealing (TA) was performed to FeSiBNbCu nanocrystalline powder cores (NPCs), and the magnetic properties, microstructure, and magnetic domain structure were in detail studied comparing with those after normal annealing (NA), and the mechanism of the improvement of soft magnetic properties by TA was elucidated. The experimental results show that the core loss of the sample is reduced by 14 % and the coercivity is reduced by 38 % after TA at 450 °C compared to the NA sample. The direct current bias performance of the TA sample is maintained at 67 % under a 100 Oe bias field. TA optimizes the soft magnetic properties of NPCs by optimizing the domain structure, reducing the formation of micro-vortex dots and broadening the size of the domain. These results can provide a good guide for optimizing the performance of NPCs with low core loss at high frequency. 相似文献
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The magnetic properties of annealed Fe42Co42Nb7B8Cu0.5Ni0.5, Fe42Co42Nb6B8Cu1Ni1 and Fe42.5Co42.5Nb6B8Cu0.5Ni0.5 alloys produced by melt spinning have been studied. By simultaneous addition of Cu and Ni elements, the soft magnetic properties of nanocrystalline FeCoNbB alloy with high Curie temperature were greatly improved. The annealed alloys show high Curie temperature of more than 1223 K and excellent soft magnetic properties, i.e., low coercivity of about 30 A/m and high effective permeability of above 5000, and these values are superior to the typical nanocrystalline HITPERM alloys for high temperature applications. 相似文献
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《Materials Research Bulletin》2004,39(7-8):1029-1035
In the present work, in order to elucidate the mechanism of magnetic relaxation in Fe-based nanocrystalline alloy ribbons at low fields and low frequencies, the dependence of the dynamic magnetization properties of nanocrystalline alloy ribbons on the thickness of ribbons has been investigated by permeability spectroscopy. The agreement of the experimental results with the domain wall motion equations confirms that domain wall bulging between the pinning edges is the dominant magnetization mechanism at low fields and low frequencies. 相似文献