Fe-Si-B非晶粉末及其磁粉芯研制进展概述

本文概述了带材破碎制备Fe78Si9B13非晶合金粉末及其磁粉芯的制备与性能研究;铁硅硼合金是制备磁粉芯的理想原料;球磨气流复合破碎法是带材破碎制粉的有效途径之一;通过不同磁导率非晶磁粉芯产品的磁性能测试,证明Fe78Si9B13非晶磁粉芯是综合性能良好的一种新型磁粉芯.     

FeSiB-La合金的非晶形成能力和磁阻抗效应

将稀土La元素掺杂Fe78Si9B13合金,采用单辊法制备了FeSiB-La非晶带材,再将非晶带材在不同温度下进行退火处理。用DSC和XRD分析了带材的非晶形成能力和晶化行为,用阻抗分析仪测试了非晶带材的磁阻抗效应。结果表明,掺杂稀土La元素可提高带材的非晶形成能力,延缓带材中Fe-Si、Fe-B晶化相的析出,增强带材的热稳定性;Fe Si B-La非晶带材的磁阻抗效应随测试频率的升高和磁场强度的增大而增大;随退火温度升高,非晶带材的磁阻抗效应呈先增大后减小的趋势。     

铁基非晶及纳米晶合金在NaOH溶液中的耐蚀性比较

冶炼制备了纳米晶Fe73.5Si13.5B9Nb3Cu1和非晶带材Fe78Si13B9。在电化学工作站上测试了两种合金在不同浓度的NaOH碱溶液里的极化曲线。随着NaOH溶液浓度的不同,非晶Fe78Si13B9和纳米晶Fe73.5Si13.5B9Nb3Cu1合金极化曲线具有相似的变化规律,且纳米晶合金比非晶合金的腐蚀电位要高,耐腐蚀性要好。     

带材破碎制备Fe_（78）Si_9B_（13）非晶合金粉末及其磁粉芯性能

对带材破碎法制备Fe78Si9B13非晶合金粉末及其磁粉芯的性能进行了研究。球磨气流复合破碎法是带材破碎制粉的有效途径之一。通过与美国Magnetics相同磁导率磁粉芯产品的磁性能对比,证明Fe78Si9B13非晶磁粉芯是综合性能良好的一种新型磁粉芯。     

Ni对FeCuNbSiB纳米晶合金恒导磁性能的影响

采用成分为Fe73.5Cu1Nb3Si15.5B7(at%)和Fe74-xNixCu1Nb3Si15B7(x=1,3)、Fe76-xNixCu1Nb3Si11B9(x=5、7、10、15)的非晶合金带材卷绕成环形铁芯,分别进行普通热处理和磁场热处理后检测铁芯磁性能。结果表明,随合金中Ni含量的增加,铁芯磁导率明显降低,可达到1.2k;交流损耗值比Fe73.5Cu1Nb3Si15.5B7合金铁芯降低了一个数量级;添加Ni元素后,铁芯抗直流性能明显改善,这是由于合金的磁畴结构发生了细化,感生磁各向异性增强而引起的。     

Fe74Al4 Sn2(PSiBC)20块体非晶合金的制备与晶化研究

利用铜模吸铸法制备了φ5mm×8mm×1mm的Fe74Al4Sn2P10Si4B4C2和Fe74Al4Sn2P11 C4B4Si1块体非晶合金圆环.Fe74Al4Sn2P10Si4B4C2和Fe74Al4Sn2P11C4B4Si1块体非晶合金具有较高的约化玻璃转变温度(Tg/Tm≈0.60).Fe74Al4Sn2P10Si4B4C2块体非晶合金的晶化过程是二步晶化非晶相→非晶相'+α-Fe→α-Fe+Fe3P+Fe2B+Fe3B+Fe3C,而Fe74Al4Sn2P11C4B4Si1块体非晶合金的晶化过程是一步晶化非晶相→α-Fe+Fe3P+Fe2B+Fe3B+Fe3C.一步晶化的Fe74Al4Sn2P11C4B4Si1块体非晶合金具有更宽的超冷液相区.二步晶化的Fe74Al4Sn2P10Si4B4C2块体非晶合金的热磁曲线分为四个阶段室温→Tg→Tx→Tp1→高温,而一步晶化的Fe74Al4Sn2P11G4B4Si1块体非晶合金的热磁曲线分为三个阶段室温→Tg→Tx→高温.α-Fe的析出导致铁基块体非晶合金饱和磁化强度值Ms上升,而结晶化合物Fe3P、Fe2B、Fe3B和Fe3C的同时析出导致Ms值的下降.     

微稀土化非晶带材的晶化行为和磁阻抗效应

将稀土La元素掺杂Fe73.5Cu1Nb3Si13.5B9合金,采用单辊法制备了FeCuNbSiB-La合金带材。用XRD分析了带材的晶化行为,用阻抗分析仪测试了带材的磁阻抗效应。结果表明,淬火态FeCuNbSiB-La合金带材为非晶态结构,经550℃晶化热处理后的FeCuNbSiB-La(0.5wt%)非晶带材形成了非晶和纳米晶双相共存结构;FeCuNbSiB-La非晶带材的磁阻抗效应随测试频率的升高和磁场强度的增大而增大,随稀土La元素含量的增大呈先增大后减小的趋势。     

Fe80Si9B11非晶合金薄带热膨胀特性和结构弛豫分析

提出了采用推杆式热膨胀仪测试非晶合金薄带热膨胀特性的新方法。分析了Fe80Si9B11非晶薄带的热膨胀曲特性和非晶合金晶化过程。根据R．G．Zheng理论分析了结构弛豫中自由体积比变化,发现自由体积比曲线出现双峰。结合晶化前发生相分离的理论分析了这种变化的原因。分析表明：铁基非晶Fe80Si9B11晶化过程中先形成a—Fe（Si）相,再析出FesB、二次a—Fe（Si）相。晶化前先发生相分离,自由体积比增大,然后析出结晶相a—Fe（si）,自由体积比降低。随温度升高,B偏聚,自由体积比增大,随后析出Fe3B、二次a—Fe（Si）相,自由体积比降低。     

热处理条件对Fe78Si9B13非晶合金磁性能的影响

部分晶化法是一种具有实用前景的Fe78Si9B13非晶合金热处理方法。研究了不同热处理温度、热处理时间、保护气氛及冷却速度对Fe78Si9B13非晶合金磁性能的影响,探讨了获得具有一定恒导磁性能Fe78Si9B13非晶合金磁芯的方法。随热处理温度的上升,Fe78Si9B13非晶磁芯0A下的电感量单调下降,1A下的电感量先上升后下降。在一定保温温度和保护气氛下,随热处理时间的延长,Fe78Si9B13非晶磁芯0A下电感量单调减小,1A下电感量单调增加。较低的保温温度有利于在较宽保护气氛下获得所需磁性能的磁芯,过高真空度不利于获得所需的磁芯性能。不同冷却速度对Fe78Si9B13非晶磁芯电感量没有明显影响。     

退火温度对Fe_(78)Si_9B_(13)非晶带材软磁性能的影响

采用单辊法制备了宽20 mm、厚25μm的Fe78Si9B13非晶带材,再将非晶带材进行不同温度的退火处理,研究了退火温度对其软磁性能的影响。结果表明,随退火温度的升高,Fe78Si9B13非晶带材的初始磁导率、饱和磁感应强度、矫顽力和电感呈先增大后减小的趋势;当退火温度达到400℃时,其综合软磁性能最佳,初始磁导率为6.648 K,饱磁感应强度为1.517 T,矫顽力为15.73 A/m。当退火温度达到450℃时,其磁导率受磁场强度的影响很小,呈现出恒导磁特性。     

高饱和磁感Fe82Si3.8B13.9C0.3非晶铁芯的退火及浸漆工艺

研究了不同磁场退火和浸漆固化工艺对Fe₈₂Si_3.8B_13.9C_0.3非晶合金环形铁芯损耗和磁性能的影响,并与1K101合金铁芯进行了对比。结果表明:与1K101合金相比,Fe₈₂Si_3.8B_13.9C_0.3合金铁芯的最佳退火温度低于1K101合金,其中纵磁退火时达到最低,为330 ℃。纵磁退火Fe₈₂Si_3.8B_13.9C_0.3合金铁芯有着更高的饱和磁感应强度,B_{3500 A/m}=1.611 T。经350 ℃无磁场退火处理后,Fe₈₂Si_3.8B_13.9C_0.3合金铁芯的损耗P_{50 Hz, 1.4 T}=0.360 W/kg,稍高于1K101合金;经330 ℃纵磁退火处理后,Fe₈₂Si_3.8B_13.9C_0.3合金铁芯的损耗P_{50 Hz, 1.4 T}=0.257 W/kg,也高于1K101合金;经350 ℃横磁退火处理后损耗P_{50 Hz, 1.4 T}=0.163 W/kg,低于1K101合金。纵磁退火Fe₈₂Si_3.8B_13.9C_0.3合金铁芯经浸漆固化处理后,磁通密度B_{800 A/m}=1.341 T,比纵磁退火1K101合金浸漆固化铁芯高15%;纵磁退火且浸漆的Fe₈₂Si_3.8B_13.9C_0.3合金铁芯损耗低于1K101合金浸漆铁芯,且随着频率升高优势更加明显;当频率大于1000 Hz时,纵磁退火且浸漆的Fe₈₂Si_3.8B_13.9C_0.3合金铁芯的损耗值低于未浸漆铁芯。     

Magnetic properties of nanocrystalline Finemet alloys with Co addition

This report focuses on ac magnetic properties of (Fe_0.5Co_0.5)_73.5Cu₁Nb₃Si_13.5B₉ alloy in the high temperature. The effects of replacing 50% Fe by Co in Fe_73.5Cu₁Nb₃Si_13.5B₉ alloy on the static magnetic properties have also been studied. Addition of Co leads to an increase around 110 K of the Curie temperature of the amorphous phase, much higher than Ge-containing Finemet alloy. The material has much better ac magnetic properties than Hitperm alloy. An excellent stability of initial permeability in high temperature (up to 650 K) and high frequency (up to 5 × 10⁵ Hz) can be observed with respect to the Co-free alloy.     

新型Fe72.7Si17B6.8Nb2.6Cu0.9纳米晶铁芯的磁场热处理工艺与软磁性能

为满足高频变压器对铁芯低损耗的需求,研究了新型Fe_72.7Si₁₇B_6.8Nb_2.6Cu_0.9纳米晶铁芯的热处理工艺,探讨了铁芯动态、静态软磁性能随无磁场退火保温时间与施加不同磁场强度的横磁磁场退火时的变化规律。结果表明,不加磁场时,保温时间为60 min时铁芯的损耗最低,为P_{20 kHz/0.5 T}=11.82 W/kg,而其静态软磁性能在保温30 min处于最优状态,H_{c30 min}=1.86 A/m。施加横向磁场后,其直流磁性能剩磁和矫顽力显著降低,H_{c40 mT}=0.64 A/m,而其损耗在磁场强度为50 mT达到最低,为P_{20 kHz/0.5 T}=10.53 W/kg。高频范围内涡流损耗在铁芯损耗中起主导作用,新型纳米晶铁芯经横向磁场热处理后高频损耗大幅降低,同时磁导率表现优异。     

Formation and Structural Evolution of Fe_(72.5)B_(15.6)Si_(7.8)Nb_(1.7)Zr_(1.7)Cu_(0.7) Nanocrystalline Alloy

A 2.5-mm Fe_(72.5)B_(15.6)Si_(7.8)Nb_(1.7)Zr_(1.7)Cu_(0.7) glassy rod was successfully fabricated using copper mold casting.The introduction of Cu resulted in the formation of large quantities of a-Fe nanoparticles embedded in the glassy matrix after isothermal annealing.The Fe_(72.5)B_(15.6)Si_(7.8)Nb_(1.7)Zr_(1.7)Cu_(0.7) nanocrystalline alloy exhibited high saturation magnetization(～1.26 T) and a low coercive force(～0.8 A/m) after annealing at 833 K for 15 min due to the precipitation of ～15-nm-sized a-Fe nanoparticles in the glassy matrix.The structural evolution of the FeBSiNbZrCu amorphous alloy during the annealing process was discussed using a dual-cluster model.     

Small-angle neutron scattering and differential scanning calorimetry studies on the copper clustering stage of Fe–Si–B–Nb–Cu nanocrystalline alloys

The kinetics of copper clustering and primary crystallization of FINEMET type alloys with the compositions Fe_74.5−xSi_13.5B₉Nb₃Cu_x and Fe₇₇Si₁₁B₉Nb_3−xCu_x have been studied by small-angle neutron scattering (SANS) and high-sensitivity differential scanning calorimetry (DSC) in order to explain the different optimized Cu contents, x, for obtaining the highest permeability in these two alloys. SANS results have shown that the alloys with the optimized Cu contents have the finest nanocrystalline microstructures. Kinetic analyses of Cu clustering prior to primary crystallization have shown that the number density of Cu clusters becomes highest at the crystallization stage of -Fe primary crystals in the alloy containing an optimized amount of Cu.     

High permeability nano-crystalline FeSiBTaAg ribbons obtained by direct casting

Nano-crystalline soft magnetic ribbons, being extensively used as magnetic cores for switching power supplies, have been invariantly obtained by melt-spinning followed by post-annealing. Reported herewith are the attainment, by direct-casting without annealing, of nano-crystalline Fe_77.4−xSi_15.5B₇Ta_xAg_0.1 (x = 1, 2) ribbons with superior soft magnetic properties (named TAGMET after the addition of Ta and Ag). The grain size of nano-crystalline -FeSi, from 20 to 30 nm, varies with composition and quenching speeds. As-spun Fe_75.4Si_15.5B₇Ta₂Ag_0.1 ribbons consisting of 25 nm nano-crystals exhibit a saturation magnetization of 157 emu/g (1.45 T), an effective permeability of 56,000 at 1 kHz, and coercivity, 8 A/m. With the combination of easier manufacturing process and excellent soft magnetic properties, this alloy is competitive in industrial applications versus the well-known FINEMET.     

Ni合金化对Finemet合金热稳定性及软磁性能的影响

通过铜辊甩带法制备了成分为Fe_73.5-xSi_13.5B₉Cu₁Nb₃Ni_x(x=0、1、2、3)的非晶带材,并对其进行退火处理。利用XRD、DSC、VSM和软磁直流测试仪等对带材的相结构、热稳定性以及软磁性能进行测试分析。结果表明,所制备合金带材淬火态下均为完全非晶结构,经560 ℃保温60 min退火处理后,合金中形成了非晶和α-Fe(Si)纳米晶双相共存结构。随着Ni含量的增加,整体上非晶带材的一级起始晶化温度T_s1和二级起始晶化温度T_s2先减小后增大,两级起始晶化温度之差ΔT_s整体呈下降的趋势,由166.0 ℃下降至132.8 ℃,热稳定性降低。淬火态下,Ni元素的添加使得非晶带材的软磁性能有所恶化。经退火处理后,带材的软磁性能明显提升,当Ni含量x=1时,具有较好的软磁性能,其饱和磁化强度为157.7 emu/g,矫顽力为6.8 Oe。     

Structural properties and evaluation of crystal fraction by cryogenic heat capacity measurements of Fe-based nanocrystalline alloy

An amorphous Fe_73.5Cu₁Nb₃Si_13.5B₉ alloy was prepared by the rapid solidification technique. The rapidly quenched alloys have been annealed in the temperature range from 490 to 550 °C for 90 min and their structure was investigated by using X-ray diffraction (XRD). After annealing, at crystallization temperature, the microstructure of the samples composed of nanocrystalline Fe₃Si grains surrounded by the residual amorphous phase. The crystal fractions of the annealed samples were evaluated by heat capacity measurements. Heat capacities of the as-quenched and annealed samples were measured at different temperatures between 15 and 40 K. This method is useful for evaluating small changes in the amount of crystalline phase and provides a new tool for finding the nanocrystalline fraction. The volume fraction of the crystalline phase increased from 15.92 to 94.21% as annealing temperature increased from 490 to 550 °C.     

The role of tensides in the covering, formation and power loss properties of amorphous metallic ribbons by glassy coatings

Tensides are surface active substances which play an essential role in the formation of glassy coatings from aqueous solutions of H₃BO₃, H₃PO₄ and their salts. Firstly, they ensure the wettability of the hydrophobic metallic ribbon at the phase boundary in very low concentrations and, in addition, they adjust both specifically and effectively the reaction conditions between the depositing solution and the surface of the amorphous metallic ribbon. They penetrate into the interlayer of the ribbon changing its physico-chemical properties and in this way influence its magnetic characteristics. This paper deals with the effect of commercially produced non-ionic tensides (Slovanik NT, Slovasol EL, Slovasol O) and an anionic tenside (Slovafos 3) in the process of the formation of glassy coatings vs. power loss for amorphous Fe₈₂Si₆B₁₂, Fe₄₀Ni₄₀B₂₀ and Co₇₀Fe₅Si₇B₁₈ ribbons. The influence of different amounts of tensides in borate and phosphate deposition solutions and of heat treatment of these solutions on power loss is discussed.     

Microstructural evolution of Fe3B/Nd2Fe14B nanocomposite magnets microalloyed with Cu and Nb

The microalloying effect of Cu and Nb on the microstructure and magnetic properties of an Fe₃B/Nd₂Fe₁₄B nanocomposite permanent magnet has been studied by transmission electron microscopy (TEM) and atom probe field ion microscopy (APFIM). Additions of Cu are effective in refining the nanocomposite microstructure and the temperature range of the heat treatment to optimize the hard magnetic properties is significantly extended compared with that of the ternary alloy. Combined addition of Cu and Nb is further effective in reducing the grain size. Optimum magnetic properties obtained by annealing a melt-spun Nd_4.5Fe_75.8B_18.5Cu_0.2Nb₁ amorphous ribbon at 660°C for 6 min are B_r=1.25 T, H_cJ=273 kA/m and (BH)_max=125 kJ/m³. The soft magnetic Fe₂₃B₆ phase coexists with the Fe₃B and Nd₂Fe₁₄B phases in the optimum microstructure of the Cu and Nb containing quinternary alloy. Three-dimensional atom probe (3DAP) results show that the finer microstructure is due to the formation of a high number density of Cu clusters prior to the crystallization reaction, which promote the nucleation of the Fe₃B phase. The Nb atoms appear to induce the formation of the Fe₂₃B₆ phase when the remaining amorphous phase is crystallized.