表面处理和温度对非晶/纳米晶磁芯软磁性能的影响

用宽20 mm、厚25μm的Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9非晶带材绕制成环形磁芯,再经550℃×100 min晶化退火处理制成非晶/纳米晶磁芯。研究了环氧树脂封装和测试温度对其软磁性能的影响。结果表明,与环氧树脂封装前相比,封装后的起始磁导率、最大磁导率、饱和磁感应强度和电感减小;矫顽力、磁滞损耗和剩磁增大;磁化曲线和磁滞回线基本上重合。随测试温度的升高,环氧树脂封装前后的起始磁导率和电感均呈先增大后减小的趋势;饱和磁感应强度均减小;矫顽力均增大。     

纵向磁场热处理对高饱和磁感应强度Fe基非晶-纳米晶软磁性能的影响

以单辊快淬法和非晶晶化法制备的(Fe_(66)Co_(20)B_(14))_(100-x)Cu_x(x=0.7,1)系列非晶/纳米晶合金带材为研究对象,利用X射线衍射法表征母相合金的晶体结构。利用差示扫描量热法标定其热力学性能以及晶化过程。采用纵向磁场热处理的工艺方法制备纳米晶材料。研究在外加磁场强度恒定的条件下,退火温度对样品软磁性能的影响。采用振动样品磁强计、阻抗分析仪、交直流B-H仪等测定了该合金的软磁性能。结果表明,该合金在淬态条件下具有强的玻璃形成能力、高的热稳定性以及高的饱和磁感应强度。纵向磁场热处理在提高该合金饱和磁感应强度、降低矫顽力方面卓有成效,并且在高频条件下可使该合金的损耗值维持在较低的范围。     

铁基非晶带材热处理工艺及磁性能研究

本文研究了不同的热处理工艺对4种FeSiB非晶合金带材性能的影响.研究结果表明,这4种非晶合金带材的损耗和工作磁感应强度Bm与最佳热处理温度有关,最佳热处理温度越高.其工作磁感应强度Bm也越高.当Bm接近Bs时,激磁功率会激增.经最佳热处理温度处理后,铁含量较低的非品合金的软磁性能要优于铁含量较高的非晶合金以及传统的铁...     

FeSiB/FeCuNbSiB合金在NaOH溶液中耐腐蚀性能及其对软磁性能的影响（英文）

非晶Fe78Si9B13和纳米晶Fe73.5Cu1Nb3Si13.5B9合金由于具有低矫顽力、高磁导率和高饱和磁通密度等特点而受到广泛关注。研究了Fe78Si9B13及Fe73.5Cu1Nb3Si13.5B9合金在NaOH(pH=9~10)溶液中的耐腐蚀性能,及其对软磁性能的影响。分析了经腐蚀后合金的有效磁导率、矫顽力和饱和磁感应强度等软磁性能的改变。样品用X射线衍射和3D高景深显微镜进行表征。结果显示:腐蚀后溶液中有橙色铁的氧化物产生,合金结构保持不变。经腐蚀后Fe78Si9B13及Fe73.5Cu1Nb3Si13.5B9合金的软磁性能下降,且Fe78Si9B13非晶合金的有效磁导率ue和饱和磁感应强度Bs比Fe73.5Cu1Nb3Si13.5B9纳米晶合金下降快。     

Corrosion Resistance of FeSiB and FeCuNbSiB Alloys and Its Influence on Their Soft Magnetic Properties in NaOH Solution

非晶Fe78Si9B13和纳米晶Fe73.5Cu1Nb3Si13.5B9合金由于具有低矫顽力、高磁导率和高饱和磁通密度等特点而受到广泛关注。研究了Fe78Si9B13及Fe73.5Cu1Nb3Si13.5B9合金在NaOH(pH=9~10)溶液中的耐腐蚀性能,及其对软磁性能的影响。分析了经腐蚀后合金的有效磁导率、矫顽力和饱和磁感应强度等软磁性能的改变。样品用X射线衍射和3D高景深显微镜进行表征。结果显示:腐蚀后溶液中有橙色铁的氧化物产生,合金结构保持不变。经腐蚀后Fe78Si9B13及Fe73.5Cu1Nb3Si13.5B9合金的软磁性能下降,且Fe78Si9B13非晶合金的有效磁导率ue和饱和磁感应强度Bs比Fe73.5Cu1Nb3Si13.5B9纳米晶合金下降快。     

热等静压对铁基非晶纳米晶合金软磁性能的影响

在铁基非晶纳米晶合金,普通氮气热处理最佳退火温度的基础上,将热等静压工艺引入到非晶带材磁芯的退火工艺中,探究热等静压工艺对Fe基非晶纳米晶合金软磁性能的影响。用X射线衍射仪、精密磁性元件测试仪和软磁交流设备测量了铁基非晶带材的晶体结构、磁芯的电感L和磁损耗P_s等。结果表明,在频率100 kHz和工作磁感应强度B_m=0.1 T时,普通氮气保护退火样品的矫顽力和磁损耗为2.04 A/m、10.10 W/kg,而热等静压样品则为1.33 A/m、6.58 W/kg,分别降低了53.4%、34.9%;普通氮气保护退火样品的有效磁导率和品质因数为11 579、0.46,而热等静压则为15 980、0.70,分别增加了38.0%、52.2%。     

新型块体铁基非晶合金的形成与性能

利用铜模铸造法制备了(Fe100-xCox)74Mo6P10C7.5B2.5(x=0-15)新型块体铁基非晶合金。Fe-Co-Mo-P-C-B系块体非晶合金具有临界直径为4mm的高非晶形成能力,以及维氏硬度为10.6～10.85GPa的高硬度和饱和磁感应强度为0.98～1.07T的优异性能。研究结果表明,非晶合金硬度及饱和磁感应强度都随着Co含量的提高逐渐增加。合金的非晶形成能力则与Co的含量密切相关。适量Co的添加扩大非晶合金的过冷液体区间(ΔTx)及增加γ值,从而提高非晶合金的热稳定性及其非晶形成能力。     

非晶和纳米结构磁性材料

软磁材料有以硅钢板、坡莫合金、仙台合金以及铁氧体为代表的结晶材料 ,还有近年来发展起来的非晶合金、纳米晶合金以及纳米粒状组织合金。非晶、纳米晶材料不同于传统材料 ,其突出特点是能够人工控制其原子级的组织结构。自从 70年代初开发成功非晶软磁材料以来 ,相继又发现了优于非晶合金的高饱和磁通密度、高频高磁导率铁系纳米晶合金 ,近年来又开发了高频特性优越的金属 -非金属纳米颗粒构造的软磁材料。非晶合金之所以成为性能优越的划时代软磁材料 ,因为它的原子排列无序因而无“各向异性” ,没有结晶、晶界、空洞之类宏观的组织“紊…     

非晶软磁合金的技术特性及工业应用

从应用的角度来看,非晶软磁合金分为两大类:①高导磁非晶合金,它相当于1J79、1J85及1J86这一类坡莫合金.此类非晶合金的成分大体上是以CoNiFe及CoFe为基的.②高饱和磁感应强度非晶合金,它相当于1J50、1J52和1J34这一类坡莫合金及硅钢.此类非晶合金的成分是以铁为基的,这是因为从应用前途来看铁的价格便宜.由磁学的唯象理论得知,获得高磁导率的必要条件是磁晶各向异性常数K及磁致伸缩系数λ同时趋于零.而非晶合金由于处于长程无序的状态所以先天地不存在K.这样就     

FeCuNbSiB铁基非晶纤维制备及退火性能研究

用扫描电镜和X射线衍射仪观察和分析了熔融快淬法制备的FeCuNbSiB铁基非晶纤维,对影响制备的工艺因素进行了研究,测量了纤维制备态和退火态的电阻率和比饱和磁化强度。结果表明,用快淬法制备的纤维处于非晶态,制备态纤维的电阻率比经300、450、500℃加热1h退火处理后的高;随退火温度升高,纤维的电阻率和比饱和磁化强度减小,体积分数增大,非晶相减少。纳米晶相的形成明显影响纤维饱和磁化强度的变化。     

Multi-phase nanocrystallization induced fast degradation of methyl orange by annealing Fe-based amorphous ribbons

Different from the common understanding that crystallization deteriorates the degradation capability of amorphous alloys, we show here that the Fe-based multi-phase nanocrystalline ribbons (Fe-MNRs) exhibit 3 and 17 times higher degradation rate than its amorphous counterpart and the conventional zero valent iron powders, respectively. The formation of multi-phase nanocrystals and nanoporous structure resulted from selective corrosion during degradation is responsible for the high degradation capability of Fe-MNRs. The present results suggest that suitable nano-crystallization annealing treatment could be a novel approach to enhance the degradation capability of Fe-based amorphous alloys.     

Fabrication and Characterization of Thermal-Sprayed Fe-Based Amorphous/Nanocrystalline Composite Coatings: An Overview

This review focuses on the recent development of iron (Fe)-based amorphous/nanocrystalline composite coatings, which have attracted much attention due to their attractive combination of high hardness/strength, elevated abrasive wear resistance, and enhanced corrosion resistance. Accompanying the advancements in various thermal spray technologies, industrial application fields of Fe-based amorphous/nanocrystalline composite coatings are becoming more diverse. In the main part, the typical empirical rules for the design of amorphous alloys with high glass-forming ability are generalized and discussed at first. Then various thermal spray technologies for the fabrication of Fe-based amorphous/nanocrystalline composite coatings, such as high velocity oxygen/air spray (HVOF/HVAF), air plasma spray (APS), low-pressure plasma spray (LPPS), high-energy plasma spray (HPS), and high velocity arc spray (HVAS) processes, are introduced. The microstructures, hardness, wear resistance, and corrosion resistance of Fe-based amorphous/nanocrystalline composite coatings formed using these thermal spray technologies are reviewed and compared. Finally, the existing challenges and future prospects are proposed.     

廉价高BS超低铁损纳米晶软磁合金

本文简要介绍了Bs达1.8～1.94T并且工作Bm达1.5～1.7T时的铁损优于细畴高取向硅钢的Fe-CuSiB(P)系Fe基纳米晶合金的最新研究进展.     

Influence of High-temperature Oxidation on Soft Magnetic Properties of Fe78Si9B13 Amorphous Alloy

研究了高温氧化对铁基非晶Fe78Si9B13合金软磁性能的影响。结果表明:非晶Fe78Si9B13合金带材经高温氧化处理后,在其表面形成了一层厚度约为10μm的高电阻率铁的氧化物层;Fe78Si9B13合金高温氧化磁化变得困难,且饱和磁感应强度Bs由氧化前的Bs=1.42~1.46 T下降到氧化后的Bs=1.29~1.38 T。同时,对非晶Fe78Si9B13合金带材经高温氧化处理后磁化困难的原因进行了讨论。     

Cold-consolidation of ball-milled Fe-based amorphous ribbons by high pressure torsion

Cold-consolidation using high pressure torsion (HPT) has been applied to ball-milled Fe-based amorphous ribbons to process bulk disks of approximately 9 mm in diameter and 0.3 mm in thickness. The mainly amorphous bulk samples demonstrated soft magnetic behavior, higher Curie temperature and enhanced microhardness with respect to the ribbons.     

New Fe-based soft magnetic amorphous alloys with high saturation magnetization and good corrosion resistance for dust core application

Fe-rich amorphous dust core alloys with minor-addition of Mo and/or Cr were synthesized because of the industrial request of mass production of high efficient low core loss Fe-based dust cores. It was found that the present Fe-(Cr, Mo)-P-B-Si-(C) amorphous alloy ribbons exhibit good soft magnetic properties of above 1.5 T for saturation magnetization, below 10 A/m for coercivity and rather good corrosion resistance in 3%NaCl aqueous solution. Besides, the amorphous alloy ribbons exhibit good bending ductility in as-spun and optimally annealed states. It is noticed that these characteristics are much superior to those for commercial Fe-Cr-Nb-P-B-Si soft magnetic dust core alloy (SENNTIX). In addition, the annealing treatment was noticed to cause the improvement of corrosion resistance without detriment to bending ductility. The new Fe-based soft magnetic alloys with good combined characteristics are expected to be used as the basic material as high-efficient soft magnetic dust cores in a high frequency range.     

Formation and performance of an Fe-based amorphous-nanocrystalline composite coating by laser cladding and remelting

Abstract

A very important research topic in the area of the surface performance of engineering components, in particular their wear properties, recently has been the application of high quality surface layers on relatively cheap substrates. An Fe-based composite coating with both amorphous and nanocrystalline structures on a mild steel substrate offers a combination of high quality coating and low materials cost, at the same time extending the range of applications of traditional materials. The difficulties posed by preparation of Fe-based amorphous alloys have limited progress for many years. However, the recent development of high power lasers, and of laser material processing technology in general, has made the preparation of a Fe-based amorphous and nanocrystalline composite coatings over a large area a real possibility.     

Selective dissolution of amorphous and nanocrystalline Zr2Ni

Rapidly quenched Zr₂Ni amorphous and nanocrystalline ribbons were subjected to electrochemical selective dissolution. The porous structure of the dealloyed materials showed a dependence on the alloy microstructure. The etching takes place with constant rate in three dimensions, indicating a surface controlled dissolution process. The etching rate of the amorphous alloy was found to be lower than for the nanocrystalline material. Partial crystallization of the de-alloyed amorphous ribbon has been observed. The electrocatalytic activity for Hydrogen evolution reaction of the selectively dissolved amorphous and nanocrystalline ribbons was found to be improved compared to the as-cast alloys.     

Effect of Ca addition on soft magnetic properties of nanocrystalline Fe-based alloy ribbons

The effect of Ca addition on the magnetic properties of a nanocrystalline Fe-based alloy was investigated. A small amount of Ca (0.06 wt%) was added to the Fe-based alloy, which was then melt spun to fabricate thin ribbons with a thickness of ∼30 μm. These ribbons were heat treated to obtain a nanocrystalline structure with a grain size of ∼10 nm, and the crystallization behavior was studied to optimize the grain structure. The characteristics of the ribbon alloys were analyzed using a B-H meter, a 4-point probe, a transmission electron microscope (TEM), and a scanning electron microscope (SEM). As a result, the optimum permeability and minimum core loss were obtained for the alloy containing Ca, when annealed at 520 °C for 1 h. The analyses revealed that a reduced core loss could be attributed to the high electrical resistivity and suppressed grain growth, which were caused by the Ca element distributed along the grain boundary. Based on the results, Ca addition to Fe-Si-B-Nb-Cu base nanocrystalline alloy was very effective in controlling the grain size, minimizing the eddy current loss, inducing an improved magnetization behavior, and reducing the core loss.     

STUDIES ON PRIMARY CRYSTALLIZATION OF RAPIDLY QUENCHED Al-Ni-Cu-Nd METALLIC GLASS BY USING HIGH RESOLUTION TRASMISSION ELECTRON MICROSCOPY

Rapidly solidified Al87Ni7Cu3Nd3 metallic glasses, prepared by using melt spinning, were treated under both isothermal and non-isothermal regime. The amorphous ribbon and the annealed samples were closely examined by means of differential scanning calorimetric, conventional X-ray diffraction and high resolution transmission electron microscopy with selected-area electron diffraction, with special interest in primary crystallization into α-Al nanocrystalline particles, in order to understand structural characteristics of Al-based amorphous/nanocrystalline alloys, and nucleation and grain growth mechanism on the nanometer scale during primary crystallization. The results show that, the as-prepared ribbons are fully amorphous and homogeneous in the micron scale, but contain high density of quenched-in clusters or crystallite embryos. Primary crystallization mainly leads to formation of two-phase mixture of a-Al crystal and residual amorphous phase. The annealed ribbons exposed isother-mally at HOP C for 5