纳米铁氧体包覆对铁基非晶磁粉芯性能的影响及其机理研究

Due to the characteristics of constant magnetic permeability, high resistivity, low core loss and temperature stability under high frequency, Fe-based amorphous magnetic powder core is an important development direction of magnetic powder core materials. However, in order to reduce the core loss under high frequency of the amorphous magnetic powder cores, a lot of non-magnetic insulated and cementing materials were used during the process of preparation, decreasing the permeability and saturation magnetic induction intensity of the magnetic powder cores, which is not conducive to the miniaturization of electronic components. In order to solve the above problems, this project intends to adopt of soft magnetic ferrite powder as insulating agent, to decrease the content of non-magnetic materials and to prepare a new type of Fe-based amorphous composite magnetic powder core. At the same time, by changing the types of soft magnetic nano-ferrite powder, particle size distribution and contents, to research the influence on the interface structure and soft magnetic properties of the Fe-based amorphous magnetic powder cores, and to establish the relationship between interface structure, soft magnetic properties and preparation process parameters. By studying the influence of different interface structure on the domain shape, size, and the domain movement law of the magnetic powder core in the process of magnetization, to reveal the mechanism of improving the permeability and other properties of the Fe-based amorphous magnetic powder cores by coating the soft magnetic ferrite nanoparticles on the surface of the amorphous magnetic powders, which can provide experimental and theoretical guidance to improve the soft magnetic properties of the Fe-based amorphous magnetic powder cores. The implementation of the project is of great significance on the promotion of the development of electronic components and related industry.

铁基非晶磁粉芯在高频下具有恒磁导率、高电阻率、低损耗和温度稳定性好等特点，是磁粉芯材料的重要发展方向。但是，为了降低非晶磁粉芯在高频下的损耗，在制备过程中加入了大量的非磁性绝缘和粘结物质，导致其磁导率和饱和磁感应强度降低，不利于电子元器件的小型化。为解决以上问题，本项目拟采用纳米软磁铁氧体粉末作为绝缘剂，降低非磁性物质的含量，制备出新型铁基非晶复合磁粉芯，同时，通过改变纳米软磁铁氧体粉末的种类、粒径分布及含量，研究其对铁基非晶磁粉芯界面结构及软磁性能的影响规律，建立界面结构、软磁性能与制备工艺参数间的相互关系；研究不同界面结构对磁粉芯磁畴形状、大小及在磁化过程中磁畴运动的影响规律，揭示纳米软磁铁氧体包覆提高磁粉芯磁导率及软磁性能的机理，为提高铁基非晶磁粉芯的磁性能提供实验和理论指导。本项目的实施对促进电子元器件及相关行业的发展具有重要意义。

铁基非晶磁粉芯在高频下具有恒磁导率、高电阻率、低损耗和温度稳定性好等特点，是磁粉芯材料的重要发展方向。但是，为了降低非晶磁粉芯在高频下的损耗，在制备过程中加入了大量的非磁性绝缘和粘结物质，导致其磁导率和饱和磁感应强度降低，不利于电子元器件的小型化。为解决以上问题，本项目采用气雾化法制备了球形非晶粉末，并系统研究了绝缘包覆工艺对非晶磁粉芯性能的影响以及微观结构与磁性能的关联等内容。研究发现，通过调控热处理温度，获得了在100 kHz，0.1 T条件下，损耗小于600 mW/cm3的铁基非晶磁粉芯，通过采用超声分散法，实现了纳米铁氧体在非晶磁粉表面的均匀包覆，在非晶磁粉间获得厚度均匀，包覆完全的纳米铁氧体及环氧树脂界面，阐明了界面结构对非晶磁粉芯软磁性能的影响机理，并通过优化制备及热处理工艺，显著提高了非晶磁粉芯的磁导率。同时，揭示了纳米软磁铁氧体包覆提高磁粉芯磁导率及软磁性能的机理，为提高铁基非晶磁粉芯的磁性能提供实验和理论指导。本项目研究结果对促进电子元器件及相关行业的发展具有重要意义。