耐热冲击NiZn功率铁氧体材料的研究

发布时间：2018-04-18 00:15

本文选题：NiZn功率铁氧体 + 磁导率　；参考：《电子科技大学》2014年硕士论文

【摘要】：本论文以高性能耐热冲击和高机械强度NiZn功率铁氧体材料为研究目标,优先保证优异的电磁性能,如高磁导率、高饱和磁感应强度、高密度、高电阻率、低损耗等符合功率铁氧体要求的材料技术指标。选择满足技术指标的样品,进行耐热冲击和机械强度的实验,根据实验结果,从掺杂和工艺两方面出发,研究分析影响铁氧体磁芯耐热冲击和机械强度的因素和机理,提出提高镍锌软磁铁氧体磁芯耐热冲击和机械强度的方法。具体内容包括:1、分别研究Co2+、Cu2+取代和Zn2+对镍锌功率铁氧体物相、磁性参数和微观结构的影响。根据实验结果,选取合适的工艺条件、离子取代以及取代量,来达到我们所需要的材料指标。实验结果表明,在相同取代量变化范围,Co和Cu呈现出显著不同的变化趋势。由于过渡液相烧结促进致密化和显微结构的完善而增加烧结,Cu取代样品具有更高的饱和磁感应强度、起始磁导率和更低的相对损耗因子。2、研究二磨掺杂WO3,CaCO3-SiO2的复合掺杂,WO3-SiO2的复合掺杂,一磨掺杂Bi2O3,分别对镍锌功率铁氧体磁性参数和微观结构的影响,根据实验结果,选取合适的工艺条件、掺杂离子以及掺杂量,来达到我们的要求。添加适当比例的WO3可以提高烧结密度,减少气孔的产生,晶粒均匀性会更好,这都会有利于样品的耐热冲击性能。加入CaCO3-SiO2组合增加晶界的厚度,以此来增强试样的机械强度和耐热冲击性能。微量的Bi2O3掺杂,在降低烧结温度的同时,有望改善功率铁氧体材料的显微结构。3、首先对热冲击断裂和损伤理论、铁氧体材料强度这两方面的理论进行了叙述,并分别分析了影响两者的一些关键因素。利用第三章掺杂得到的一些样品进行实验,探讨了影响铁氧体磁芯耐热冲击和机械强度的因素和机理,建立微结构控制模型,揭示工艺条件和不同的掺杂体系对气孔和晶粒分布的影响规律,进而影响试样耐热冲击性能和机械强度。晶粒细小,分布均匀,气孔率低都是提高材料耐热冲击性能和机械强度的首选途径。
[Abstract]:In this paper, high performance heat shock and high mechanical strength NiZn power ferrite materials are the research targets, and the excellent electromagnetic properties, such as high permeability, high saturation magnetic induction intensity, high density, high resistivity, are preferred.Low loss and other material technical specifications that meet the requirements of power ferrite.The thermal shock and mechanical strength of ferrite core were studied and analyzed from the aspects of doping and processing according to the experimental results of thermal shock and mechanical strength of the ferrite core, which met the technical specifications, and the factors affecting the thermal shock and mechanical strength of the ferrite core were studied and analyzed.A method to improve the thermal shock and mechanical strength of nickel zinc soft magnetic ferrite core is proposed.The effects of Co2 Cu2 substitution and Zn2 on the phase, magnetic parameters and microstructure of Ni-Zn power ferrite were studied.According to the experimental results, the suitable technological conditions, ion substitution and substitution amount were selected to meet the material requirements.The experimental results show that the variation trends of Co and Cu in the same range of substitution amount are significantly different.Because the transition liquid phase sintering promotes the densification and the microstructure improvement, the higher saturation magnetic induction intensity is obtained by increasing the sintered Cu substitution sample.The initial permeability and lower relative loss factor. 2. The effects of mixed doping of WO _ 3C _ 3-SiO _ 2 and Bi _ 2O _ 3 on the magnetic parameters and microstructure of Ni-Zn power ferrite were studied.The appropriate process conditions, doping ions and doping amount were selected to meet our requirements.Adding a proper proportion of WO3 can increase the sintering density, reduce the production of pores, and improve the grain uniformity, which will be beneficial to the thermal impact properties of the samples.The mechanical strength and thermal impact properties of the samples were enhanced by adding CaCO3-SiO2 combination to increase the thickness of grain boundary.The microamount of Bi2O3 doping is expected to improve the microstructure of power ferrite materials at the same time as decreasing sintering temperature. Firstly, the theory of thermal shock fracture and damage and the strength of ferrite materials are described.Some key factors affecting the two factors are analyzed respectively.Based on the experimental results of some samples doped in the third chapter, the factors and mechanisms affecting the thermal shock and mechanical strength of ferrite cores are discussed, and the microstructure control model is established.The effects of process conditions and different doping systems on porosity and grain distribution were revealed, and the thermal impact properties and mechanical strength of the samples were further affected.Fine grains, uniform distribution and low porosity are the preferred ways to improve the thermal impact properties and mechanical strength of the materials.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM277

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