高性能FeSiBMCu纳米晶合金的制备及性能研究

发布时间：2018-06-30 01:01

  本文选题：纳米晶合金 + 软磁性能　； 参考：《太原理工大学》2017年硕士论文

【摘要】：铁基纳米晶合金是由非晶合金经过热处理得到的一种具有纳米晶结构的软磁材料。正是由于这种独特的纳米晶结构,铁基纳米晶合金具有优异的软磁性能:低的矫顽力(Hc)、高的饱和磁感应强度(Bs)和磁导率(μe)以及接近于零的磁致伸缩系数等,可以有效地降低铁芯损耗和噪声。因此,铁基纳米晶合金被广泛地应用于开关电源、高精密电流/电压互感器、共模扼流线圈、高频变压器等电力电子领域。Finemet合金是目前得到广泛应用的纳米晶软磁材料之一,但是此合金具有贵金属Nb元素含量高、Bs低等缺点。为了降低生产成本、提高Bs,本文通过降低Nb含量提高Fe含量,成功开发出了兼具高Bs和优异软磁性能的FeSiBNbCu纳米晶合金;用抗氧化性好的Mo元素替代Nb元素,解决了高Fe含量的FeSiBNbCu表面晶化的问题;以高Fe含量的FeSiBNbCu为对象,研究了表面晶化程度对软磁性能的影响。主要的研究内容和研究结果如下所示:(1)成功开发出了兼具优异软磁性能和高热稳定性的高频高Bs的Fe78-xSi13B8NbxCu1(x=0,1,2和3)纳米晶合金,系统地研究了 Nb元素的含量对FeSiBNbCu合金体系软磁性能、热稳定性及微观结构的影响。研究发现,通过添加适量的Nb元素,Fe76Si13B8Nb2Cu1纳米晶合金平均晶粒尺寸可达10nm左右,同时具有优异的软磁性能,即高Bs(1.39T)、低Hc(1.5A/m)和高μe(21500,在1 kHz下)。此合金具有宽达100℃的热处理温度区间和长达60 min的热处理时间区间,说明此合金具有优异的热稳定性和软磁性能。(2)成功开发出了Bs高达 1.74 T 的 Fe82Cu1Si4B11.5Nb1.5-xMox(x=0,0.75和1.5 at.%)纳米晶合金体系,并研究了 Mo元素对此体系非晶形成能力、软磁性能及微观结构的影响。研究发现Mo元素的添加可以提高合金的非晶形成能力,但添加微量的Mo效果不明显。经过热处理以后,所有的合金具有优异的软磁性能,即高的Bs(1.67～1.74T),低的Hc(8.9～10.8A/m),和高的μe(11500～11900在1 kHz下)。此外,含Mo合金具有更优异的高频特性,使得此合金有望应用于高频电力电子设备。(3)利用Fe82Cu1Si4B11.5Nb1.5纳米晶合金随着铜辊转速变化而具有不同结构的现象,研究了表面晶化程度对软磁性能、热稳定性和微观结构演化的影响。研究发现表面晶化样品的热处理温度区间比完全非晶态的样品更宽,适量的表面晶化可以降低铁芯损耗,但是过度晶化会导致铁芯损耗的增高。最后,从扩散和竞争过程两方面讨论了表面晶化的纳米晶合金带材的晶化过程,认为晶化过程是受扩散和竞争过程共同驱动的。
[Abstract]:Fe-based nanocrystalline alloy is a soft magnetic material with nanocrystalline structure obtained by heat treatment of amorphous alloy. It is precisely because of this unique nanocrystalline structure that Fe-based nanocrystalline alloys have excellent soft magnetic properties: low coercivity (HC), high saturation magnetic induction (Bs) and permeability (渭 e), and near zero magnetostrictive coefficient, etc. It can effectively reduce core loss and noise. Therefore, Fe-based nanocrystalline alloys are widely used in switching power supply, high-precision current / voltage transformer, common-mode choke coil, high-frequency transformer and other power electronics fields. Finemet alloy is one of the widely used nanocrystalline soft magnetic materials. However, the alloy has the disadvantages of high NB content and low Bs content. In order to reduce production cost and increase Bscontent, FeSiBNbCu nanocrystalline alloy with high Bs and excellent soft magnetic properties was successfully developed by reducing NB content and increasing Fe content, and NB element was replaced by Mo element with good oxidation resistance. The problem of surface crystallization of FeSiBNbCu with high Fe content was solved, and the effect of the degree of surface crystallization on the soft magnetic properties of FeSiBNbCu with high Fe content was studied. The main research contents and results are as follows: (1) Fe78-xSi13B8NbxCu1 (xOOONbCu 2 and 3) nanocrystalline alloys with excellent soft magnetic properties and high thermal stability have been successfully developed, and the soft magnetic properties of FeSiBNbCu alloy system have been systematically studied. Effects of thermal stability and microstructure. It is found that the average grain size of Fe 76Si13B 8Nb 2Cu 1 nanocrystalline alloy is about 10nm by adding proper amount of NB element, and it has excellent soft magnetic properties, I. e., high Bs (1.39T), low Hc (1.5A/m) and high 渭 e (21500, at 1 kHz). The alloy has a wide heat treatment temperature range of 100 鈩，

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