微胞软磁复合材料的绝缘包覆及性能研究

发布时间：2018-04-24 08:23

  本文选题：放电等离子烧结 + 软磁性复合材料　； 参考：《长春工业大学》2015年硕士论文

【摘要】：变压器和电感器是计算机、航空航天和自动化等电子信息领域主要设备的重要元件,轻薄性和高度集成化的发展趋势,使其引起了人们的广泛关注,这也要求软磁铁芯具有良好的高频特性。目前,铁氧体和非晶合金带材是常用的高频软磁性材料。铁氧体虽电阻率较高但饱和磁感应强度和磁导率较低,非晶合金制备设备复杂,加工难度大,且其电阻率远小于铁氧体,仍有待改善,此外其涡流损耗也较大,并非理想的高频软磁材料。因此,研究开发饱和磁感应强度高、磁导率大、矫顽力小、损耗低且易于成型的软磁材料是工业发展的必然要求。软磁性复合材料(Soft magnetic composite materials,SMCs)是指通过复合方法在铁磁性粉末颗粒表面包覆高电阻率的物质制备出具有高电阻率、高磁导率的一种软磁性材料。SMCs的制备借助粉末冶金技术的优势,可显著降低高频涡流损耗,将在航天、军事、电子科技以及其他领域得到广泛应用。本文通过物理包覆方法和放电等离子烧结(SPS)技术,选用Fe76Si9B10P5非晶微米粉末作为基体合金,Zn0.5Ni0.5Fe2O4纳米铁氧体粉末作为包覆层,在487℃烧结制备了具有优异软磁性能的Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4块体非晶软磁复合材料。烧结样品界面出现约70 nm薄层熔化结晶组织,表明烧结过程中局域瞬时高温的存在,由此阐释了其特殊的SPS烧结机理,由于等离子体的产生和新的放电通路以自蔓延模式不断形成,在样品内界面处形成局域瞬时高温,Zn0.5Ni0.5Fe2O4纳米粒的尖端效应促进了放电过程,且在电流作用下,碰撞电离也极大地促进了放电和等离子体的产生,由放电热产生的局域瞬时高温实现了Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4复合材料的烧结和致密化过程。此外,通过溶胶凝胶法和SPS技术,烧结由MgO纳米粉末包覆的Fe-6.5Si微米级颗粒。在600 MPa压力下,550℃烧结制备了具有优异软磁性能的Fe-6.5Si/MgO块体非晶软磁复合材料。分析了SPS脉冲电流对烧结过程及样品致密化的影响,脉冲电流促进了MgO绝缘颗粒间的桥接,可产生大量的焦耳热促进烧结过程。对添加不同含量的MgO制备的SMCs的显微组织、软磁性能及力学性能进行分析,结果表明在合金材料中适量添加MgO包覆层,可制得具有良好软磁性能的微胞SMCs,如高的电阻率、高的饱和磁感应强度、低的矫顽力等。有望在中高频环境下得到广泛应用。通过溶胶凝胶化学包覆方法制备的纳米软磁性复合材料包覆层更加均匀稳定,厚度可控,其综合性能更加优异,可望广泛适用于高性能电机、高频变频元件、变压器及传感器等软磁性零(器)件中,以实现生产轻量化和大功率化,对现代工业尤其是对网络通讯、军工领域、电子科技产业具有明显的实际意义。
[Abstract]:Transformer and inductor are important components in electronic information field, such as computer, aerospace, automation and so on. The development trend of lightness and high integration has caused people's widespread concern. This also requires that the soft magnetic core has good high frequency characteristics. At present, ferrite and amorphous alloy strip are commonly used in high frequency soft magnetic materials. Although the resistivity of ferrite is high, the saturation magnetic induction intensity and permeability are low, the preparation equipment of amorphous alloy is complex, the processing is difficult, and its resistivity is much smaller than ferrite, which still needs to be improved, in addition, its eddy current loss is also larger. Not ideal high frequency soft magnetic material. Therefore, the research and development of soft magnetic materials with high saturation magnetic induction, high permeability, low coercivity, low loss and easy forming are necessary requirements of industrial development. Soft magnetic composite material MCs is a kind of soft magnetic material with high resistivity and high permeability, which is prepared by composite method on the surface of ferromagnetic powder particles. The preparation of soft magnetic material. SMCs has the advantage of powder metallurgy technology. It will be widely used in aerospace, military, electronics and other fields. In this paper, Fe76Si9B10P5 amorphous micron powder was chosen as the coating layer of Zn0.5Ni0.5Fe2O4 nano-ferrite powder by physical coating method and spark plasma sintering (SPS) technique. Bulk Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4 bulk soft magnetic composites with excellent soft magnetic properties were sintered at 487 鈩，

本文编号：1795881