Fe73.5Cu1Nb3Si13.5B9非晶合金的晶化动力学

用差热分析（ＤＴＡ）结合Ｘ射线衍射（ＸＲＤ）,研究了Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９非晶合金的晶化动力学。结果表明：温度在０～７００℃范围内,该合金的晶化相为α－Ｆｅ和Ｆｅ２Ｂ;α－Ｆｅ相晶化表观激活能为４５２．３９ＫＪ／ｍｏｌ,Ｆｅ２Ｂ相的晶化表观激活能３９５．２３ＫＪ／ｍｏｌ;两相在晶化初期激活能最小,随晶化量Ｘｃ的增加而迅速境大,在α－Ｆｅ的体积分类为３０％～８０％,Ｆｅ２Ｂ的体积分     

Fe73.5CulNb3Si13.5B9非晶合金的晶化动力学

用差热分析(DTA)结合X射线衍射(XRD),研究了Fe73.5Cu1Nb3 Si13.5B9非晶合金的晶化动力学.结果表明:温度在0～700℃范围内,该合金的晶化相为α-Fe和Fe2B;α-Fe相晶化表观激活能为452.39 kJ/mol,Fe2B相的晶化表观激活能395.23 kJ/mol;两相在晶化初期激活能最小,随晶化量Xc的增加而迅速增大,在a-Fe的体积分数为30%～80%,Fe2B的体积分数为40%～80%时,呈现极大值.     

Fe73.5Cu1Nb3Si13.5B9非晶合金电脉冲处理与等温退火的比较

用直流高密度电脉总和可比等温退火处理Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９非晶合金,并用ＸＲＤ,ＴＥＭ和穆斯堡尔谱方法进行了结构检测。结果表明,在电脉冲作用下,Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｐ９非晶合金在平均温度为４２０℃的条件下发生了纳米晶化,晶化度试样中无Ｆｅ－Ｂ相析出,无ＤＯ３型有序结构;晶化总量达３０．９％的无序ａ－Ｆｅ（Ｓｉ）相的平均尺寸为８～９ｎｍ,按二项式分布计算ａ－Ｆｅ（Ｓ     

W、Nb对Fe76.5Cu1Si13.5B9非晶合金晶化行为的影响

用热分析法结合ＸＲＤ、ＴＥＭ研究了添加元素Ｗ、Ｎｂ对Ｆｅ７６．５Ｃｕ１Ｓｉ１３．５Ｂ９非晶合金晶化行为的影响。结果表明,Ｗ或Ｎｂ的加入都降低了Ｆｅ－Ｃｕ－Ｓｉ－Ｂ非晶合金反应的Ａｖｒａｍｉ指数ｎ;并且添加元素Ｎｂ更有利于该合金获得较小的ａ－Ｆｅ（Ｓｉ）晶粒。     

Fe73.5Cu1Nb3Si13.5B9纳米晶的微结构

本文分别用ＪＥＯＬ－２０００ＦＸ分析电镜和ＪＥＯＬ－２０００ＥＸⅡ高分辨电镜研究了经磁场热处理的Ｆｅ７３．５Ｃｕ１Ｎｂ８Ｓｉ１３．５Ｂ９纳米晶中Ｆｅ（Ｓｉ）固溶体晶粒的大小、形状、晶粒间的接触及取向关系，重元素的偏聚和非晶基体的有序性等微观结构。     

超微晶合金Fe73.5Cu1Nb3Si13.5B9晶化过程的X射线研究

用Ｘ射线衍射方法研究了超微晶合金Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９在退火过程中晶化相及晶格常数的变化。经４８０℃×１ｈ退火后，合金中出现ｂｃｃＦｅ（Ｓｉ）相，６００℃出现Ｆｅ３Ｂ相，６７０℃出现Ｆｅ２３Ｂ６相。退火温度升高时，Ｆｅ（Ｓｉ）相的晶格常数由０．２８３８ｎｍ上升到０．２８４９ｎｍ合金经过５５０℃×４ｈ退火后仍只有Ｆｅ（Ｓｉ）一个晶化相，其晶格常数随时间的变化不明显。     

Fe76.5Cu1Si13.5B9非晶合金晶化过程的X射线衍射研究

Fe_(76.5)Cu_1Si_(13.5)B_9非晶合金在晶化过程中析山的α-Fe固溶体(α相)的X射线衍射峰存在不对称性并随退火温度而变化,对α相衍射峰进行分峰拟合证实,Cu原子可以促进α相形核并固溶其中,合金晶化与原始态中残存晶核无关,α相晶粒中Cu含量的不同导致衍射峰的不对称性,键合能准化学近似计算结果表明,Cu原子降低了周围原子的迁移势垒,导致合金的晶化首先在含Cu量较高的区域开始,使晶化温度降低。     

机械合金化对Fe73.5Cu1Nb3Si13.5B9纳米晶合金结构的影响

研究Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９纳米晶合金在机械合金化过程中的结构的变化，发现将已经形成纳米晶的合金带经过短时间的机械球磨以后可以使它变非晶态粉末，若延长球磨时间可使非晶粉末再出晶化，并具有更步的晶粒。若将以非晶态粉末再进行退火可形成晶粒更微小的纳米晶。     

脉冲电流处理对Fe73.5Cu1Nb3Si13.5B9合金薄带GMI效应的影响

本文研究了脉冲电流处理对Fe73.5Cu1Nb3Si13.5B9合金薄带巨磁阻抗效应和脆性的影响,并与等温退火样品的巨磁阻抗效应和脆性进行对比.结果表明,经过应力脉冲电流处理后的样品,其阻抗变化率和灵敏度都显著高于无应力脉冲处理后的样品.淬态样品在9.34MPa拉应力下,经电流密度为930A/mm2的脉冲电流处理后,阻抗变化率可达到220%,灵敏度达到0.35%/A·m-1.用应力脉冲电流处理不仅可以显著提高巨磁阻抗效应,而且可以有效抑制样品长时间的等温退火带来的脆性问题.     

Fe73.5Cu1Nb3Si13.5B9软磁合金晶化处理

利用综合热分析仪测量了Fe73.5Cu1Nb3Si13.5B9晶化处理的焓变和晶化温度,并制定了不同的晶化退火工艺,利用振动样品磁强计自动测量仪对晶化处理后的试样进行了磁性能测定.研究结果表明,Fe73.5Cu1Nb3Si13.5B9软磁合金从250 ℃开始加热,经过370 ℃、470 ℃二次预热处理,在560 ℃保温1 h后,炉冷到250 ℃出炉冷却,可获得较高的软磁性能.     

The absorbing properties of Fe73.5Cu1Nb3Si13.5B9 amorphous powder/S-glass fiber-reinforced epoxy composite panels

Fe73.5Cu1Nb3Si13.5B9 (or FeCuNbSiB) powder/ S-glass fiber-reinforced epoxy composite panels were prepared by mold pressing method. Metallographic analysis shows that the amorphous powders are evenly distributed between the layers of S-glass fibers. The effects of the FeCuNbSiB powder mass fraction on the complex permittivity, complex permeability, and microwave absorption of the composite panels have been studied in the frequency range of 2.6-18.0 GHz. The complex permittivity of the composite panels with different mass fractions of the FeCuNbSiB powders shows several peaks in the 2.6-18.0 GHz frequency range. The complex permeability of the composites decreases with the increasing frequency in the frequency range of 8-18 GHz. The composite with FeCuNbSiB/epoxy mass ratio of 2.5:1.0 has excellent microwave absorption properties of a minimum reflection loss value-30.5 dB at 10.93 GHz for a thickness of 2 mm. A reflection loss exceeding-10 dB can be obtained in a broad frequency range of 3.2-18.0 GHz with a thickness of 1.15-5.00 mm. For the FeCuNbSiB composites, the magnetic loss is the dominant term for microwave absorption. The FeCuNbSiB powders are a possible candidate for high-performance microwave absorption filler.     

退火工艺对Fe73.5Cu1Nb3Si13.5B9纳米晶带材耐腐蚀性能的影响

采用电化学方法研究了退火工艺对Fe73.5Cu1Nb3Si13.5B9纳米晶带材耐腐蚀性能的影响.用差热分析仪分析了该纳米晶带材的晶化过程,利用X射线衍射仪对经不同温度退火后的非晶带材的晶态结构进行了分析,并用恒电位法测试了样品在3.5%NaCl溶液中的耐腐蚀性能.结果表明,在3.5%NaCl溶液中,经过不同温度退火后的Fe73.5Cu1Nb3Si13.5B9纳米晶带材的耐腐蚀性能随退火温度的升高呈先增加后降低的趋势,其中530 ℃退火后的样品具有最好的耐蚀性.     

Fe73.5 Cu1 Nb3 Si13.5 B9机械合金化纳米晶粉末的特种烧结及磁性能

研究了放电等离子烧结和高压烧结工艺条件对MA Fe73.5Cu1Nb3Si13.5B9纳米晶粉末的烧结块体合金的组织结构与磁性能的影响.结果表明:球磨70 h后,获得了单相a-Fe纳米晶(约9.5 rm)过饱和固溶体粉末;DSC升温曲线中,出现4个不同强度的放热峰,依次发生了纳米晶过饱和固溶体的结构弛豫、非晶晶化以及过饱和固溶体相析出等过程,且相析出过程分两个阶段完成;在p=30 MPa,t=5 min放电等离子烧结(SPS)条件下,当温度达到1 050℃后,可获得相对密度为98.9%、主相为α-Fe的纳米晶(100nm)块体合金,其中,B3=1.34 T,Hc=7.34 kA/m,在p=5.5 GPa,t=5 min条件下,当Pw=1 150 W后,可获得相对密度约99.1%、单相α-Fe纳米晶(21.4 nm)块体合金,其中,Bs=1.14 T,Hc=8.22 kA/m.     

纳米晶Fe_（73．5）Cu_1Nb_3Si_（13．5）B_9合金中缺陷及内应力的分布研究

用正电子湮没技术和微观磁学方法研究了纳米晶Ｆｅ_（７３．５）Ｃｕ_（１）Ｎｂ_（３）Ｓｉ_（１３．３）Ｂ_９合金结构缺陷在退火过程中的变化规律，表明晶化初期形成的界面结构只引入少量的缺陷，晶化后期由于出现大量晶界，缺陷浓度急剧上升；非晶制备过程中以及晶化时引入的准位错偶极子造成的应力场对其软磁性能有很大的影响，并可以解释在最佳退火温度的磁性行为。     

Fe73.5Cu1Mo3Si13.5B9超微晶磁粉芯的研究

本文对Ｆｅ７３．５Ｃｕ１ｍＯ３Ｓｉ１３．５Ｂ９超微晶合金带制作磁粉芯的工艺进行了研究。特别对粉的粒度，成形压力，绝缘的配比以及磁粉芯的磁性能进行了深入的探讨。发现磁粉芯的性能与制粉用的微晶带材是否具有优良磁性能无关。通过调整绝缘剂量及其组分可以使磁粉芯的磁性能发生相应的变化。超微晶粉的粒度对磁粉芯的性能及频率特性起着决定的作用。     

Microstrucural characterization of gas atomized Fe73.5Si13.5B9Nb3Cu1 and Fe97Si3 alloys

Powder particles of Fe_73.5Si_13.5B₉Nb₃Cu₁ and Fe₉₇Si₃ soft magnetic alloys have been prepared by gas atomization. The gas atomized powder was microstructurally characterized and the dependence of coercivity with the composition and powder particle size investigated. As-atomized powder particles of both compositions were constituted by a bcc α-Fe (Si) solid solution. The Fe_73.5Si_13.5B₉Nb₃Cu₁ powder particles presented a grain microstructure with dendrite structure, which dendrite arms were enriched in Nb. The coercivity increased as the particle size decreased, with a minimum coercivity, of 5 Oe, measured in the Fe₉₇Si₃ alloy in the range of 50–100 μm powder particle size. The coercive fields were quite higher in the Fe_73.5Si_13.5B₉Nb₃Cu₁ than in the Fe₉₇Si₃ powder, due to the Nb addition, which produced a phase segregation that leads to a noticeable magnetic hardening.     

Cu clustering and Si partitioning in the early crystallization stage of an Fe73.5Si13.5B9Nb3Cu1 amorphous alloy

Solute clustering and partitioning behavior in the early crystallization stage of an Fe_73.5Si_13.5B₉Nb₃Cu₁ amorphous alloy have been studied by employing a three-dimensional atom probe (3DAP) and a high resolution electron microscope (HREM). Results from the 3DAP have clearly shown that Cu atom clusters are present in the amorphous state after annealing below the crystallization temperature. The density of these clusters is in the order of 10²⁴/m³, which is comparable to that of the α-Fe grains in the optimum nanocrystalline microstructure. In the early stage of primary crystallization, Cu clusters are in direct contact with the α-Fe nanocrystals, suggesting that the α-Fe primary particles are heterogeneously nucleated at the site of Cu clusters. In the early stage of crystallization, the concentration of Si is lower in the primary crystal than in the amorphous matrix phase, unlike in the late stage of the primary crystallization, where Si partitions into the α-Fe phase with a composition of approximately 20 at.%.