高饱和磁感应强度铁基非晶、纳米晶研究进展

本文介绍了高饱和磁感应强度铁基非晶、纳米晶带材研究进程,总结了高饱和磁感应强度铁基非晶、纳米晶带材设计原理以及目前的合金体系,高饱和磁感应强度的获得主要与Fe的含量以及内部特殊结构有关;最后简要讨论了研究成果应用于大规模工业生产的可行性。     

稀土改性非晶带材的制备与软磁性能研究

利用稀土La掺杂Fe73.5Cu1Nb3Si13.5B9非晶合金,成功制备了稀土La改性的非晶带材.对制得的非晶带材进行热处理和显微组织分析,最后测试了带材的软磁性能.结果表明添加La改变了非晶带材的晶化温度,随着La含量的增加,晶化温度呈下降趋势.显微金相分析表明带材表面存在纹路,且纹路随着热处理温度的变化而变化.带材中内应力分布不均造成带材的厚度随温度变化而波动.La原子加入后使非晶带材的尺寸波动范围变窄,尺寸波动的临界温度也由400℃下降到300℃;在550℃×0.5 h热处理工艺时,FeCuNbSiB(La-0.5wt%)带材综合软磁性能最佳,饱和磁感强度可达到1.7 T以上,磁导率为5306.     

稀土改性非晶带材的制备与软磁性能研究

利用稀土La掺杂Fe73.5Cu1Nb3Si13.5B9非晶合金,成功制备了稀土La改性的非晶带材。对制得的非晶带材进行热处理和显微组织分析,最后测试了带材的软磁性能。结果表明:添加La改变了非晶带材的晶化温度,随着La含量的增加,晶化温度呈下降趋势。显微金相分析表明带材表面存在纹路,且纹路随着热处理温度的变化而变化。带材中内应力分布不均造成带材的厚度随温度变化而波动。La原子加入后使非晶带材的尺寸波动范围变窄,尺寸波动的临界温度也由400℃下降到300℃;在550℃×0.5 h热处理工艺时,FeCuNbSiB(La-0.5wt%)带材综合软磁性能最佳,饱和磁感强度可达到1.7 T以上,磁导率为5306。     

Fe69Co8Nb7-xVxB15Cu1非晶条带热稳定性与软磁性能研究

基于Slater-Pauling曲线,运用"元素替代"成分设计法则,通过单辊旋淬工艺成功制备出Fe69Co8Nb7-xVxB15Cu1(x=0,2,5,7)非晶合金条带。利用XRD、TEM和DSC对合金系的非晶形成能力、热稳定性进行研究,并通过PPMS和B-H磁滞回线仪研究合金系的软磁性能。结果表明:随着V含量的增加,合金系的非晶形成能力、热稳定性和矫顽力逐渐降低,而饱和磁感应强度、居里温度逐渐增高;当x=2时非晶合金具有最宽两次晶化温度区间,热处理温区宽达225.9℃;当x=7时非晶合金具有最佳高温软磁性能,其饱和磁感应强度为0.96 T,矫顽力仅为8.95 A/m,而居里温度高达TC=349.42℃。     

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。     

新型Fe80.5Si7.2B12.3非晶合金带材的退火工艺与磁性能

研究了新型Fe80.5Si7.2B12.3非晶合金带材在不同退火工艺下的磁性能及磁损耗特性,并与传统的铁基非晶合金Fe80Si9B11进行了对比.结果表明:新型Fe80.5Si7.2B12.3非晶合金带材比Fe80Si9B11具有更高的饱和磁感应强度,在励磁磁场强度为3500 A/m下其磁通密度值为1.607 T;在f...     

退火工艺对FeSiB非晶带材脆性的影响

研究了热处理工艺对FeSiB非晶带材韧性的影响情况，结果表明．当退火温度为300℃时，FeSiB非晶带材开始慢慢晶化，当温度上升到500℃时，带材内部结构已由非晶态完全转变成晶态。退火温度对非晶带材的脆化起决定作用，退火温度越高，带材脆化程度越大，250℃是带材脆化的临界温度。当保温时间低于临界脆化时间时，带材脆化程度随时间逐渐上升。保温时间达到临界脆化时间时，带材脆化程度趋于稳定。     

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。     

Fe基高饱和磁感应强度非晶合金的研究

研究了FeCoSiB非晶合金中的Fe、Co元素之间的成分配比对非晶合金饱和磁感应强度的影响。结果表明,在Si、B含量一定的情况下,Fe与Co元素含量之比在3-4附近时,合金具有高的Bs值,并获得了饱和磁感应强度可达1．76T的铁基非晶合金。     

Effect of parameters of heat treatment on magnetic properties and magnetization distribution in ribbons of amorphous soft magnetic iron-based alloys

The effect of the isothermal-holding temperature and cooling rate upon in-air heat treatment on the magnetic properties and magnetization distribution in ribbons of amorphous soft magnetic iron-based alloys with positive saturation magnetostriction has been investigated. The results of the investigation showed that the dependence of the maximum magnetic permeability on the isothermal-holding temperature correlates with the corresponding changes in the magnetization distribution in the ribbon and is determined by diffusion processes that occur upon in-air heat treatment at a specific isothermal-holding temperature. An increase in the cooling rate leads to an ambiguous effect on the level of magnetic properties. The increase favors an improvement in magnetic properties when, after in-air heat treatment, either a predominantly amorphous state of the surface or a state with the formed amorphous-crystalline surface layer with a nearly optimal thickness is obtained.     

分步纵磁热处理对Fe3.85Co66.18Si14.5Ni0.97B14.5钴基非晶合金结构和性能的调控

为了制备低磁导率、高矩形比、低矫顽力的钴基非晶合金,对Fe_3.85Co_66.18Si_14.5Ni_0.97B_14.5非晶合金带材采用施加不同热处理工艺,且对其结构和性能进行测试分析的方式进行调控。结果表明,分步纵磁热处理之后的磁芯弛豫焓降低,致密度和有序度增加;在晶化温度之下进行退火的合金都保持非晶态;分步纵向磁场热处理可显著提升磁芯的磁学性能,且当普通热处理温度为480 ℃时,性能最佳,矫顽力0.17 A/m、矩形比96.81 %、1 kHz的有效磁导率为5675.05,且此时的磁畴呈规则的板条状,取向与外磁场呈12.8°的夹角。基于Bertitto模型对其进行损耗分离,发现满足公式P_v=11.05×f×B^0.9814_m+0.7495×f²×B²_m。     

化学镀Fe—Mo—B非晶态合金的交流磁性和结构

研究了成分及热处理对化学镀ＦｅＭｏＢ非晶态合金镀层交流磁性和结构的影响。讨论了样品在晶化过程中交流磁性和结构的变化。初步解释了样品交流磁性参数随成分的变化规律，同时研究了样品在热处理过程中损耗随退火温度的变化规律。     

EFFECT OF COMPOSITION ON PHYSICAL PROPERTIES OF AMORPHOUS Fe-Si-B ALLOYS

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Effect of chemically active medium on frequency dependence of magnetic losses in soft magnetic Fe-based amorphous alloys

The effects of the electrolytic hydrogenation and oxidation and of the interaction of the surface ribbon with water and vapor on the frequency dependence of magnetic losses per magnetization-reversal cycle are studied based on the example of soft magnetic Fe₈₁B₁₃Si₄C₂ amorphous alloy, which exhibits a positive saturation magnetostriction. It was shown that, after the hydrogenation and oxidation of soft magnetic amorphous alloys, their frequency dependences of magnetic losses per magnetization-reversal cycle, which are reduced to unit induction, exhibit groups of hydrogen- and oxygen-related peaks in the frequency ranges of 35–55 and 55–80 Hz, which can be explained by the formation of O-A and H-A atomic pairs (where A are atoms of alloy components) and their reorientation in a magnetic field in the course of magnetization reversal at certain frequencies. The formation of analogous groups of peaks for samples of soft magnetic Fe-based amorphous alloys was observed after the interaction of the ribbon surface with water and vapor and after heat treatment in air. This fact confirms the possibility of the hydrogenation and oxidation of the alloys during the aforementioned processes.     

Formation and thermal stability of amorphous Ni-Mo-P alloys

The experimental researches on the chemical deposition of Ni-Mo-P amorphous alloys were carried out by adding Na2 MoO4 into acidic solutions. The optimum technology conditions were obtained by orthogonal design experiments. The structures and the relationship between compositions and their thermal stability were studied by energy spectrum (EC), scanning electron micrograph and X-ray diffraction spectrum. Compared with Ni-P amorphous alloys, the Ni-Mo-P amorphous alloys have high crystallization temperature and thermal stability, and the hardness reaches its peak when the annealing temperature is 500 ℃. With the increase of the heat treatment temperature, the surface morphology of the alloys changes.     

Interaction of surface of ribbons of amorphous soft-magnetic iron-based alloys with vapor

The interaction with water vapor of the surface of ribbons of amorphous soft-magnetic iron-based alloys with positive saturation magnetostriction and an effect of the interaction on the magnetization distribution and magnetic properties have been investigated. The results of the investigation showed that, during in-air heat treatment, the interaction of the surface of ribbons of amorphous soft-magnetic alloys with water vapor upon the heating of samples and at the initial stage of isothermal holding exerts a substantial effect on the magnetization distribution and the level of magnetic properties formed. Preliminary room-temperature treatment of the ribbon surface in the as-quenched state with water vapor favors an increase in pseudo-uniaxial tensile stresses along the ribbon axis because, during annealing, the enhanced concentration of hydrogen and oxygen atoms introduced into the ribbon surface is formed in this direction. When certain regimes of heat treatment are used, this leads to an increase in the volume of domains with magnetization oriented along the axis of the ribbon in its plane and allows a significant enhancement in the efficiency of the in-air heat treatment.     

熔体温度对快淬法制备纳米晶复合Nd_(8.5)Fe_(77)Co_5Zr_3B_(6.5)合金微观结构和磁性能的影响

将Nd_(8.5)Fe_(77)Co_5Zr_3B_(6.5)(at%)合金熔化至不同温度后,以18 m/s的甩带速度快淬,对淬态条带进行了退火处理,分析了其微观结构和磁性能的变化。结果表明,熔体温度对淬态及其退火态合金的微观结构和磁性能可以产生重要影响,熔体温度为1210℃时制备的快淬条带由Nd_2Fe_(14)B相和部分非晶相组成,具有一定的硬磁性;随着快淬时熔体温度的升高,淬态条带中非晶相的质量分数逐渐增加,其磁性逐渐转变为软磁性。几种合金经退火处理后均由大量Nd_2Fe_(14)B相与少量软磁相组成,熔体温度较低的合金退火后其晶粒尺寸较小,磁性能较好。熔体温度为1210℃时制备的合金退火后磁性能最佳,内禀矫顽力Hci为559.2 kA/m,剩余磁化强度Br为0.98 T,最大磁能积(BH)_(max)为127.8 kJ/m~3。     

具有宽过冷液相区的多元Fe基非晶合金的热稳定性和磁性

研究了具有宽过冷液相区的Fe－（Nb）－Al-Ge-P-C-B非晶合金及其热稳定性和磁性,结果表明,少量Nb元素能够有效地提高热稳定性和玻璃形成能力,最大过冷液相区可达65．7K,非晶合金具有好的软磁性能,饱和磁化强度较高,饱和磁致伸缩系数较低,在接近晶化温度下进行退火处理能够有效地降低频顽力,改善软磁性能,晶化导致软磁性显著下降,Fe基非晶合金热稳定性的高低与其软磁性有一致性,即高热稳定性的非晶合金具有更好的软磁性能。     

Structure and magnetic characterization of amorphous and crystalline Nd–Fe–Al alloys

Glass formation has been studied in Nd₆₀Fe₃₀Al₁₀ alloy produced by melt-spinning, water quenching and copper mold chill casting. Partially amorphous alloys were obtained by melt-spinning at low wheel speeds of 5 to 15 m/s and by water quenching of a 1-mm diameter rod, while fully amorphous alloys were obtained by melt-spinning at higher wheel speeds of 20 and 30 m/s and chill casting of a 1-mm diameter rod. A high coercivity was observed in the partially amorphous ribbon melt-spun at 5 m/s and water quenched rod, and in the fully amorphous chill cast rod, while low values of coercivity were obtained in fully amorphous ribbons melt-spun at high speeds of 20 and 30 m/s. Crystallization of water quenched and chill cast samples after heat treatment at high temperature resulted in a substantial reduction of the high coercivity. Results of X-ray diffraction indicate that formation of Nd and a ternary Fe–Nd–Al phase with an unknown crystal structure were present after crystallization. TEM results and a magnetic study of the heat treated samples indicate that as long as there is an amorphous phase produced by low cooling rate, the high coercivity remains. The high coercivity of bulk amorphous samples is discussed. The unknown ternary Fe–Nd–Al phase is antiferromagnetic with a Neel temperature at about 260 K.