Si含量对FeSiBCu合金的非晶形成能力与软磁性能的影响

采用单铜辊甩带法制备了Fe（84．5-x）SixB14.5．Cu1（x=0,2,2．5,3,4）非晶合金带材,并用X射线衍射仪（XRD）、差示扫描量热仪（DSC）、振动样品磁强计（VSM）研究了Fe（84.5-x）SixB14.5Cu1合金带材的非晶形成能力、热稳定性和软磁性能。结果表明：Si元素能明显提高该体系合金的非晶形成能力,并提高了淬火态非晶合金带材的一级和二级起始晶化温度;通过合金的退火处理,合金带材析出的α—Fe纳米晶晶粒尺寸约为30nm;其中Fe（84.5-x）SixB14.5Cu1非晶合金带材经过460℃保温5min热处理后可以获得较高的饱和磁感应强度为1．82T．     

Si的添加对FeNiMoB合金非晶形成能力与软磁性能的影响

利用单铜辊甩带法制备Fe40Ni38Mo4B(18-x)Six(x=0,2,4,6,8,10和12)非晶合金带材,并用X射线衍射仪(XRD)、差示扫描量热仪(DSC)、振动样品磁强计(VSM)以及精密磁性器件分析仪研究Si元素对Fe Ni Mo BSi合金带材的非晶形成能力和软磁性能影响。结果表明,随着Si元素的添加,合金带材的矫顽力Hc先减小后增大,并在x=4时最小为5.8 A/m;Fe40Ni38Mo4B14Si4合金带材在405℃保温10 min热处理后获得较高的饱和磁化强度为112.63 A·m2/kg,在345℃保温10 min热处理后获得较低的矫顽力为7.0A/m。     

纳米晶的形成对FeCSiBPCu非晶合金软磁性能的影响

研究了Fe76-xC7.0Si3.3B5.0P8.7Cux(x=0、0.3%或0.7%(原子分数))非晶合金中Cu的添加及纳米晶的形成对其软磁性能的影响,对合金的微观结构进行了X射线衍射实验和高分辨透射电镜观察,对合金的热稳定性和晶化激活能进行了测量和分析。结果表明,该合金退火之后的饱和磁化强度与合金中α-Fe纳米晶粒的密度和大小密切相关。Cu的添加可以影响合金的非晶形成能力、热稳定性和晶化激活能,添加少量的Cu(少于0.3%(原子分数))可以有效地提高合金的非晶形成能力,抑制退火过程中α-Fe纳米晶粒的析出,增强合金的热稳定性,而当Cu的添加量达到0.7%(原子分数)时可以降低合金的晶化激活能,促进α-Fe纳米晶粒的形核,提高α-Fe纳米晶粒的密度,使合金的饱和磁化强度达到1.79T。     

Fe-Nd-B-Zr块体非晶合金的形成能力和磁性能

以Fe-Nd-B系块体非晶合金为前驱体制备永磁材料。在Fe70Nd10B20三元合金及其邻近成分点中微量添加Zr元素,采用熔体旋淬法和铜模喷注法制备样品,通过XRD和DSC表征非晶形成能力。对Fe70Nd9B20Zr1块体非晶合金进行退火晶化处理,采用XRD分析晶化产物,通过VSM表征不同晶化阶段的磁性能。结果表明,合金体系的非晶形成能力得到提高,在Zr原子分数为1%时获得临界尺寸为2mm的块体非晶合金;Fe70Nd9B20Zr1块体非晶合金在946K,600s退火时得到最佳硬磁性能,剩磁(Br)、内禀矫顽力(iHc)和最大磁能积(BH)max分别为0.54T,348kA/m和24.1kJ/m3。该合金体系可应用于直接通过铸造和热处理工艺制备块体纳米复合永磁材料。     

热处理对Fe80Zr5Nb4B11非晶合金的结构及磁性能影响

采用单辊快淬法制备Fe80Zr5Nb4B11合金,并在不同温度下对其进行退火,研究热处理对该合金的结构和磁性能的影响.利用X射线衍射(XRD)和透射电镜(TEM)表征合金的结构,利用振动样品磁强计(VSM)测量合金的磁性能.结果表明:随着退火温度的增加,α-Fe晶体相从非晶基体中析出;晶粒尺寸逐渐增大;Fe81Zr5Nb4B10合金的比饱和磁化强度(Ms)在300℃下降,之后保持持续上升的趋势;而矫顽力(Hc)的变化相对复杂,呈现先上升→下降→上升的趋势,这些特征与其微观结构密切相关.     

P对Fe基非晶合金玻璃形成能力及磁性能的影响

采用XRD、DSC、SEM、TEM和、VSM等检测方法研究了Fe(73.65-x)Ni1Al5Ga2PxB9.6Si3C5.75(x=6.65、7.65、8.65、9.65)系列合金的微观结构、玻璃形成能力及磁性能.实验结果表明,当x=8.65时,样品为非晶结构,并深入分析了此时结构中的原子团簇结构;当x=7.65时,合金为在非晶基体上析出的纳米晶结构;当x=6.65时,在非晶基体上出现了大量的晶态相复合组织.热力学分析显示,用参数7能更合理地表征合金的玻璃形成能力,为C1>C2>A4.当P含量为7.65%(原子分数)时合金具有较好的软磁性能,其矫顽力为6.0Oe,饱和磁化强度为149.4emu/g.     

软磁性Co基块体非晶合金的研究进展

Co基非晶合金不仅具有高热稳定、高强度、硬度,还显示出优异的软磁特性如低矫顽力、高磁导率、低铁损、低磁致伸缩系数等,尤其是高频下的导磁率、铁损性能极佳,有着重要的工业应用价值.但相对于软磁性Fe基非晶合金,Co基的合金体系较少、玻璃形成能力(GFA)和饱磁感应强度较低而影响了它们的广泛应用.近年,材料工作者研发出了一系列Co基块体非晶合金体系,并对它们的非晶形成机理、GFA、过冷液态稳定性、结晶化行为、磁性及力学性能等进行了广泛、深入的研究.本文对软磁性Co基块体非晶合金的研究进展进行了简述,并展望了其今后的发展方向.     

热处理工艺对Finemet软磁合金高频磁性能影响的研究

利用XRD和TEM研究了Finemet非晶软磁合金的热处理诱发纳米晶化过程中的结构和组织形貌变化,利用Scherrer公式计算了晶化过程中产生的α-Fe颗粒的尺寸大小.由XRD及TEM的相关图谱表明,Finemet非晶软磁合金的晶化过程主要发生在500℃之后,当退火温度为560℃时,纳米晶化充分且晶粒分布均匀,合金材料具有优异的软磁性能.     

Fe74Al4Ga2P12B4Si4块体非晶合金的纳米晶化及软磁性能研究

采用铜模铸造法制备了厚2mm的Fe74Al4Ga2P12B4Si4块体非晶合金.利用X射线衍射(XRD)、差热分析(DSC)和振动样品磁强计(VSM)研究了其晶化行为和软磁性能.结果表明,非晶合金的玻璃转变温度Tg为457.35℃,晶化开始温度Tx为497.65℃.合金的过冷液相区宽度△Tx达到40.30℃,表明合金具有较大的玻璃形成能力.F74Al4Ga2P12B4Si4合金的晶化是二级晶化过程.经520℃等温退火后析出α-Fe相,其晶粒尺寸为15.9nm;而经550℃等温退火后析出α-Fe相及微量的A10.3Si0.7Fe3和Fe3B相,其中α-Fe相的晶粒尺寸为17.4nm.非晶合金的饱和磁化强度为108.816emu/g、矫顽力Hc为574.97Oe;经520℃等温退火后,纳米晶合金的饱和磁化强度为106.875emu/g、矫顽力Hc为94.16Oe.退火实验结果表明,纳米晶化对材料的饱和磁化强度没有显著影响,但会显著降低材料的矫顽力.     

溅射FeSiAl合金薄膜的结构及软磁性能

Ｓｅｎｄｕｓｔ合金是制做薄膜磁头和ＭＩＧ磁头的理想材料，本工作用射频溅射法了备了Ｓｅｎｄｕｓｔ成分的ＦｅＳｉＡｌｗ合金薄膜，研究了制备对膜结构和软磁性能的影响，并对其机理进行了讨论。     

On the glass forming ability of liquid alloys

Abstract

By using the concepts of the short-range order (SRO) and middle-range order (MRO) characterizing structures, an attempt has been made to describe the glass forming ability (GFA) of liquid alloys. This includes the effect of more than two kinds of SRO in the liquid caused by the addition of second and third elements to a metallic solvent. The minimum solute concentration is related to the atomic volume mismatch estimated from the cube of the atomic radius. The optimum solute concentration for good glass formability in several binary and some ternary alloys is discussed on the basis of the empirical guideline. A new approach to obtaining good GFA of liquid alloys is based on four main factors: (i) formation of new SRO and coexistence of two or more kinds of SRO, (ii) stabilization of dense random packing structure by restraining the atomic redistribution for initiating the nucleation and growth process, (iii) formation of a stable cluster (SC) or the MRO by the harmonious coupling of SROs, and (iv) difference between SRO characterizing the liquid structure and the near-neighbor environment in the corresponding equilibrium crystalline phases. The use of interaction parameters, widely used in the thermodynamics of multicomponent metallic solutions, is proposed for effectively selecting the third solute element (X₃) for enhancing the GFA of a metallic liquid (M) containing the second solute (X₂). Fe₇₀-B₂₀-(X₃)₁₀ alloys (X₃=Cr, W, Nb, Zr and Hf) are used for illustration. Two typical model structures denoted by the Bernal and chemical-order types are used in describing the new glass structure as a function of solute concentration.     

On the glass forming ability of liquid alloys

By using the concepts of the short-range order (SRO) and middle-range order (MRO) characterizing structures, an attempt has been made to describe the glass forming ability (GFA) of liquid alloys. This includes the effect of more than two kinds of SRO in the liquid caused by the addition of second and third elements to a metallic solvent. The minimum solute concentration is related to the atomic volume mismatch estimated from the cube of the atomic radius. The optimum solute concentration for good glass formability in several binary and some ternary alloys is discussed on the basis of the empirical guideline. A new approach to obtaining good GFA of liquid alloys is based on four main factors: (i) formation of new SRO and coexistence of two or more kinds of SRO, (ii) stabilization of dense random packing structure by restraining the atomic redistribution for initiating the nucleation and growth process, (iii) formation of a stable cluster (SC) or the MRO by the harmonious coupling of SROs, and (iv) difference between SRO characterizing the liquid structure and the near-neighbor environment in the corresponding equilibrium crystalline phases. The use of interaction parameters, widely used in the thermodynamics of multicomponent metallic solutions, is proposed for effectively selecting the third solute element (X₃) for enhancing the GFA of a metallic liquid (M) containing the second solute (X₂). Fe₇₀-B₂₀-(X₃)₁₀ alloys (X₃=Cr, W, Nb, Zr and Hf) are used for illustration. Two typical model structures denoted by the Bernal and chemical-order types are used in describing the new glass structure as a function of solute concentration.     

Ti对Zr-Al-Ni非晶合金玻璃形成能力和热稳定性的影响

四元非晶形成体系中，具有相对较大玻璃形成能力和热稳定性的合金成分点位于该四元成分图的等电子浓度面和等原子尺寸面的交线上。本文以Zr60Al20Ni20非晶合金的电子浓度和原子尺寸为基础，根据等电子浓度和等原子尺寸判据，添加Ti元素，设计了一系列Zr-Ti-Al-Ni四元合金，分析了Ti元素对Zr-Al-Ni非晶合金玻璃形成能力和热稳定性的影响。研究发现，在较低的Ti含量情况下，样品主要由非晶相组成，Ti的加入降低了合金的热稳定性和玻璃形成能力。     

大块非晶形成合金液体的热物理性能与玻璃形成能力

大块非晶合金由于其优异的性能而成的具有很大潜力的新材料，而合金的玻璃形成能力（GFA）的大小是能否获得大块非晶合金的根本所在。因此研究合金的玻璃形成能力成为材料科学领域重要的研究课题。本文从液体热物理性能出发，结合在这些方面所做的研究工作对大块非晶形成合金液体的玻璃形成能力做了一些探讨，希望对大块非晶合的研究有所裨益。     

合金非晶形成能力的研究进展

在描述合金非晶形成能力的各种参数中，过冷液相区的范围△Tx和约化玻璃转变温度Trg是两个最重要最常用的参数，然而在实际应用过程中，仅用这两个参数并不能完全解释所得到的一些实验现象。于是，用来表征合金非晶形成能力的各种参数被相继提出。本文综述了各种表征合金非晶形成能力的有关参数，在这些参数中，每一参数都有其合理性与局限性，但都不能应用于所有合金系，因此，寻求一个更为合理和通用的参数以表征不同合金非晶形成能力就显得尤为迫切。     

不锈软磁合金研究

探讨了不锈软磁合金的产生、发展和应用。提出了开发不锈软磁合金、提高磁性能和耐蚀性的设计理念和方法。推荐了磁感应强度B25,电阻率ρ与合金成分关系的经验方程式。     

Enhancement of soft magnetic properties of FeCoNbB nanocrystalline alloys with Cu and Ni additions

The magnetic properties of annealed Fe₄₂Co₄₂Nb₇B₈Cu_0.5Ni_0.5, Fe₄₂Co₄₂Nb₆B₈Cu₁Ni₁ and Fe_42.5Co_42.5Nb₆B₈Cu_0.5Ni_0.5 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.     

The influence of Al content on glass forming ability and magnetic properties of high Ms nanocrystalline FeSiBPCuAl alloy

Al content on the influence of glass forming ability and magnetic properties of nanocrystalline (Fe_83.3Si₄B₈P₄Cu_0.7)_100 − xAl_x (x = 0 ∼ 1.25 at.%) alloy was investigated in our work. Experimental results show that addition of 0.5 at.% Al is effective in improving the glass forming ability of Al-free alloy and thus amorphous precursor prepared by industry-grade raw materials can be obtained. Meanwhile, the addition of Al is beneficial in decreasing coercive force and maintaining high saturation magnetization above 180 emu/g, which makes Fe-Si-B-P-Cu-Al alloy a promising soft magnetic material in potential applications.