热处理工艺对Fe-基纳米晶磁性材料高频性能的影响

发布时间：2018-05-22 10:08

本文选题：Fe-基纳米晶磁性材料 + 快速退火　；参考：《电子科技大学》2017年硕士论文

【摘要】：自从Fe-基纳米晶合金问世以来,因其优良的软磁性能,诸多学者开始对其研究报道,并取得了大量的成果。但是,在高频领域因其作为合金而具有的过高的介电常数特性,导致阻抗严重不匹配,从而影响了其高频性能。为了实现优化该材料的高频性能,本论文首先系统全面的探索了常规退火工艺对FIENMET合金的各种影响。这些探索包括退火工艺对FINEMET合金晶相成分组成的影响、不同晶相组分的特殊性质、形状因素对性能的影响等。对于Fe-基纳米晶合金来说,由于此类纳米晶合金材料的介电常数相比于磁导率来说其值太高,单独磁导率的提高对于吸波性能的提高效果并不明显。为了进一步提高样品的高频性能,必须想办法大幅降低样品的高频介电性能。科技工作者也对降低Fe-基纳米晶合金介电常数的措施做了很多探索,其中效果做最好的就是氧化包覆。这种思路简单来说,就是在高磁导率、高介电常数的样品外面包覆一层没有电磁性能的氧化物等,从而降低样品的介电常数。这种方法虽然在一定程度上可行,但是工艺流程太麻烦,需要在对样品晶化退火处理之后,再进行氧化包覆,不适合规模化生产。同时,包覆的氧化物对材料的磁导率优化以及电磁波的吸收没有任何帮助。我们对Fe-基纳米晶合金的优化方法是使用快速退火工艺处理样品。利用样品的结构特点:细小的纳米晶粒弥散的分布在具有高电阻率的非晶软磁基体上。通过快速退火工艺处理样品使样品的高电导率软磁晶相部分被高电阻率的非晶相、硬磁相等包围起来,这种方法类似于包覆处理,而且包围在软磁相上的非晶相也是磁性材料也可以参与吸收电磁波。同时,快速处理工艺由于急速达到设定温度,减少了过渡态的存在,并使晶粒来不及长大,会使晶粒细化,从而达到减小介电常数的目的,大幅优化Fe-基纳米晶的高频性能。
[Abstract]:Since the advent of Fe-based nanocrystalline alloys, due to their excellent soft magnetic properties, many scholars began to report on them, and made a lot of achievements. However, in the high frequency field, because of its high dielectric constant as alloy, the impedance is seriously mismatched, thus affecting its high frequency performance. In order to optimize the high frequency properties of the FIENMET alloy, the influence of conventional annealing process on the FIENMET alloy was studied in this paper. These researches include the effect of annealing process on the composition of crystal phase of FINEMET alloy, the special properties of different crystal phase components, and the influence of shape factors on the properties of FINEMET alloy. For Fe- based nanocrystalline alloys, because the permittivity of this kind of nanocrystalline alloy is too high compared with the permeability, the enhancement of the single permeability is not obvious. In order to further improve the high frequency properties of the samples, we must find a way to significantly reduce the high frequency dielectric properties of the samples. Scientists have also explored ways to reduce the permittivity of Fe- based nanocrystalline alloys, the best of which is oxidation coating. The simple idea is to coat the samples with high permeability and high dielectric constant with a layer of oxide without electromagnetic properties, so as to reduce the dielectric constant of the samples. Although this method is feasible to some extent, the process is too troublesome, and it is not suitable for large-scale production because it needs to be oxidized after annealing the samples. At the same time, the coated oxide is of no help to the optimization of permeability and the absorption of electromagnetic wave. We optimized the Fe-based nanocrystalline alloy by rapid annealing process. The fine nanocrystalline particles were dispersed on amorphous soft magnetic matrix with high resistivity. The high conductivity soft magnetic phase is surrounded by amorphous phase with high resistivity by rapid annealing process, and the hard magnetic field is equal. This method is similar to the coating treatment. The amorphous phase surrounded by the soft magnetic phase is also a magnetic material which can also participate in the absorption of electromagnetic waves. At the same time, the rapid treatment process can reduce the existence of transition state and make the grain grow too late, which can reduce the dielectric constant and optimize the high frequency properties of Fe-based nanocrystals.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG156;TG131

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