片状FeSiAlTi合金粉体的制备及电磁性能研究

发布时间：2018-02-05 21:17

本文关键词： FeSiAlTi合金反射损耗电磁性能球磨包覆　出处：《西华大学》2015年硕士论文　论文类型：学位论文

【摘要】：进入21世纪,科技进入到了一个爆发式增长的时代,在带来便利的同时也带来了一些麻烦。随着电子设备的普及,产生电磁波量的增加,电磁波对电子设备和生物产生的影响将不容忽视。目前针对此问题的解决方法主要是使用吸波材料来对电磁波进行衰减。金属合金粉体吸波材料有着比铁氧体更高的饱和磁化强度,更宽的吸收频段,吸波性能更好。FeSiAl合金粉体具有高磁导率,高饱和磁化强度,高电阻率,适用频带宽,吸波性能好的优点。Ti可以增加材料的电阻率,减小涡流损耗,进而提高磁导率。本文通过机械合金化和熔炼加球磨两种方法制备了FeSiAlTi合金粉体,研究了两种不同的制备工艺和不同的Ti含量对粉体结构和吸波性能的影响。在此基础上,用MgO通过高能球磨和蒸镀两种方法包覆在FeSiAlTi表面,进行了改性的研究。机械合金化方法制备的FeSiAlTi片状粉体,球磨50h,粉体粒度达到几个μm,当Ti含量为3.6wt%时,介电常数最低,反射损耗达到了最小值-30.95d B。用熔炼,球磨的方法制备FeSiAlTi片状合金粉体,球磨40h,随着合金中Ti含量的增加,晶格常数先变大,后变小,最后和没加Ti时一样。根据原子大小分析,随着Ti含量的增加,Ti在合金中将会取代Al的位置,当Ti含量为1at%和1.5at%时,合金粉体中出现了一种新相Fe0.975Ti0.025。Ti含量为1at%的粉体各原子间有合适的间距和配比,介电常数和磁导率取得了很好的匹配关系,最小反射损耗达到了-21.13dB。通过高能球磨在粉体表面包覆MgO,由于MgO没有很好包覆在粉体表面,粉体介电常数变大,吸波性能变差,反射损耗峰值移向低频。在FeSiAlTi粉体表面氧化后,通过蒸镀的方式,让Mg粉和表面氧化物在高温下发生反应,在粉体表面包覆MgO膜,品质因数Q随着频率的增加增加,??具有良好的频率稳定性,在Ti含量为1.5at%时,具有最大??。用机械合金化方法制备FeSiAlTi合金粉体时,球磨50h,Ti的含量为3.6wt%时,粉体的阻抗匹配关系最好,吸波性能最好。使用熔炼加球磨的方法制备FeSiAlTi合金时,Ti含量为1at%时可以使粉体取得最好的吸波性能。
[Abstract]:In 21th century, technology entered an era of explosive growth, bringing convenience as well as some trouble. With the popularity of electronic equipment, the amount of electromagnetic waves increased. The influence of electromagnetic wave on electronic equipment and biology will not be ignored. At present, the main solution to this problem is to use absorbing material to attenuate electromagnetic wave. Metal alloy powder absorber has more than ferrite. High saturation magnetization. With wider absorption band, the properties of FeSiAl alloy powder are better. FeSiAl alloy powder has high permeability, high saturation magnetization, high resistivity and suitable frequency bandwidth. The advantages of good absorbing property. Ti can increase the resistivity of the material and reduce the eddy current loss. In this paper, FeSiAlTi alloy powder was prepared by mechanical alloying and smelting and ball milling. The effects of two different preparation processes and different Ti content on the structure and microwave absorption properties of the powders were studied. MgO was coated on the surface of FeSiAlTi by high energy ball milling and evaporation plating. The FeSiAlTi flake powder prepared by mechanical alloying was milled for 50 h. When Ti content is 3.6 wt%, the dielectric constant is the lowest and the reflection loss reaches the minimum value of -30.95dB. The FeSiAlTi flake alloy powder was prepared by ball milling. With the increase of Ti content in the alloy, the lattice constant increased firstly and then decreased. Finally, as when Ti is not added, according to the atomic size analysis, with the increase of Ti content, Ti will replace Al in the alloy, when Ti content is 1at% and 1.5at%. A new phase with Fe0.975Ti0.025.Ti content of 1 at% was found in the alloy powder with proper spacing and proportion. The dielectric constant and permeability are well matched, and the minimum reflection loss is -21.13 dB. MgO is coated on the surface of the powder by high energy ball milling. Because MgO is not well coated on the surface of the powder, the dielectric constant of the powder becomes larger, the absorbing property becomes worse, the peak value of reflection loss shifts to the low frequency. After oxidation on the surface of the FeSiAlTi powder, the powder is deposited by evaporation. When mg powder and surface oxide react at high temperature and MgO film is coated on the surface of the powder, the quality factor Q increases with the increase of frequency. ? It has good frequency stability. When Ti content is 1.5 at%, it has the maximum frequency stability. ? When the mechanical alloying method was used to prepare FeSiAlTi alloy powder, the impedance matching relationship of the powder was the best when the content of Ti in 50 h ball milling was 3.6 wt%. When the content of Ti in FeSiAlTi alloy is 1 at%, the best absorbing property can be obtained.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.3

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