磁场处理对非晶磁粉芯性能的影响

发布时间：2018-08-17 13:50

【摘要】：非晶态软磁合金的无序密堆状原子结构不同于传统晶态金属材料,从而使其具备了高磁导率、高磁饱和强度、低的矫顽力和低损耗等优异的软磁性能。随着电子行业向小型化,轻量化,高效率和高频化发展,铁基非晶合金条带的优势不再明显,但是由非晶合金制备的非晶粉末则能实现高频化的需求。目前,球磨后的粉末由于具有不规则的形状而导致非晶态磁粉芯性能比较差并且不稳定,改善现有非晶态磁粉芯性能无论对理论指导还是工业化应用都有至关重要的意义。磁场热处理是一种改善材料结构和性能的简便方法,磁场热处理对非晶条带的报道已经很多,但对于磁粉芯影响的相关报道却很少。为了解决现有非晶态磁粉芯存在的问题,本文以最常见的Fe78Si9B13非晶合金为基础研究对象,通过对非晶态磁粉和磁粉芯进行磁场热处理,系统的研究了不同热处理工艺对软磁性能和磁畴结构的影响,进一步完善了磁场热处理对非晶磁粉芯的影响,为非晶态磁粉芯材料的工程应用提供了理论和实验指导。本论文研究内容包括下面三部分:(1)非晶磁粉在快淬和球磨过程中存在了较大的内应力,对其进行磁场预热处理、真空预热处理和不处理,再将三种非晶态磁粉进行钝化处理,绝缘包覆,添加粘接剂,并对非晶态磁粉以相同的冷压工艺进行压制成型。研究磁感应强度(B_s)、磁导率(μ)、损耗(P_(cv))和直流偏置性能的变化;通过磁力显微镜(MFM)观察预处理磁粉的磁畴。同时也研究了先钝化再进行预热处理对磁粉和磁粉芯性能的影响。(2)研究横向强磁场热处理对非晶磁粉芯性能的影响。通过扫描电子显微镜(SEM)观察不同处理阶段磁粉的形貌。当磁场强度一定时退火温度对结构和软磁性能的影响,以及磁场热处理对不同粒径分布的磁粉芯晶体结构和软磁性能的影响。(3)研究纵向微弱磁场热处理对非晶磁粉芯性能的影响,对非晶态磁粉芯进行不同时间,不同磁场强度,不同温度退火,探讨对晶体结构,复数磁导率,品质因数和损耗因子以及频率弛豫和直流偏置性能的影响。由于片状磁粉制备的磁粉芯在磁场热处理过程中存在较大的退磁场,因此也研究了球形磁粉具有较小退磁场的磁粉芯磁场热处理的效果。当外加磁场较小时,磁粉芯的性能改善的很小;随着外加磁场的增加,磁粉芯的软磁性能不断被改善,最佳磁性能也在向高频移动。
[Abstract]:The disordered dense stacked atomic structure of amorphous soft magnetic alloys is different from that of conventional crystalline metal materials, which makes them possess excellent soft magnetic properties such as high permeability, high magnetic saturation strength, low coercivity and low loss. With the development of electronic industry towards miniaturization, lightweight, high efficiency and high frequency, the advantages of Fe-based amorphous alloy strip are no longer obvious, but the amorphous powder prepared from amorphous alloy can meet the demand of high-frequency. At present, the properties of amorphous powder cores are poor and unstable due to their irregular shape, so it is very important to improve the performance of existing amorphous powder cores both in theory guidance and industrial application. Magnetic field heat treatment is a simple method to improve the structure and properties of materials. There have been many reports about the effect of magnetic field heat treatment on amorphous bands, but there are few reports on the effect of magnetic powder core. In order to solve the existing problem of amorphous magnetic powder core, the most common Fe78Si9B13 amorphous alloy is used as the research object in this paper, the magnetic field heat treatment of amorphous magnetic powder and magnetic powder core is carried out. The effects of different heat treatment processes on soft magnetic properties and magnetic domain structure are systematically studied. The effect of magnetic field heat treatment on amorphous magnetic powder cores is further improved, which provides theoretical and experimental guidance for the engineering application of amorphous magnetic powder core materials. The main contents of this thesis are as follows: (1) there is a large internal stress in the process of rapid quenching and ball milling of amorphous magnetic powder. The magnetic field preheating, vacuum preheating and non-treatment are carried out, and then the three amorphous magnetic powders are passivated. Insulation coating, addition of adhesive, and the amorphous magnetic powder in the same cold pressing process. The changes of magnetic induction intensity (Bs), permeability (渭), loss (P _ (cv) and DC bias properties were studied, and the magnetic domains of pretreated magnetic powders were observed by magnetic force microscope (MFM). At the same time, the effects of passivation and preheat treatment on the properties of magnetic powder and magnetic powder core were studied. (2) the effect of high transverse magnetic field heat treatment on the properties of amorphous magnetic powder core was studied. The morphology of magnetic powder was observed by scanning electron microscope (SEM) (SEM). The effect of annealing temperature on the structure and soft magnetic properties when the magnetic field intensity is constant. And the effect of magnetic field heat treatment on the crystal structure and soft magnetic properties of magnetic powder core with different particle size distribution. (3) the effect of longitudinal weak magnetic field heat treatment on the performance of amorphous magnetic powder core was studied. The effects of annealing temperature on the crystal structure, complex permeability, quality factor and loss factor, frequency relaxation and DC bias properties were investigated. Due to the large demagnetization in the magnetic field heat treatment process, the magnetic field heat treatment effect of the spherical magnetic powder core with small demagnetization field is also studied. With the increase of magnetic field, the soft magnetic performance of magnetic powder core is improved continuously, and the best magnetic performance is moving to high frequency.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG132.27

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