NiZn铁氧体功率损耗特性与材料微结构的关联性机理研究

The miniaturization of electronic systems prompts the development of modern power modules to the directions of miniaturization, high-frequency and chip type. Low-loss NiZn Power ferrites with high Bs (saturation magnetic flux density) is the key factor to develop the power modules with small size and high-frequency. This project intends to analyze the main factors which determine the initial permeability, Bs and power loss of the power NiZn ferrites, and provide important theoretical guidance to control and improve the experiments. Then the influences of composition, calcining temperature, powder particle size distribution and sintering curve on the microstructure and electromagnetic properties of the power NiZn ferrites will be investigated and the optimized preparation technologies will be confirmed. After that, the influences of additives on ionic placeholder, crystal structure, microstructure and macroscopic properties of the ferrites will be investigated to confirm the optimal doped technical way and grasp the correlation between the characteristics of microstructure and power loss. Finally, The high performance NiZn power ferrite can be prepared to meet the requires of small chip power inductive device applications .

电子整机系统的小型化促使现代电源模块必须向小型化、高频化和片式化方向发展，而高Bs（饱和磁感应强度）低损耗NiZn系功率铁氧体磁芯材料的研制是实现电源模块小型高频化发展的关键。本项目拟首先从机理上分析影响NiZn功率铁氧体材料起始磁导率、饱和磁感应强度及功耗特性的关键因素，为实验中如何控制和改善其磁性能提供重要的理论支撑；其次，系统研究材料配方组成、预烧温度、粒径分布以及烧结升/降温曲线等工艺参数对材料微观结构和电磁性能的影响，并创新性的提出采取纳米晶复合掺杂、价态不平衡掺杂等方法，实现对材料掺杂改性方法的突破；最后，通过深入分析各种掺杂方案对材料离子占位、晶相结构、微观形貌及宏观性能的综合影响，掌握NiZn铁氧体功耗特性与其微结构之间的关联性调控方法和规律，为研制满足小型化功率感性器件应用需求的高性能功率磁芯材料奠定充分的理论和实践基础。

本项目首先从机理上分析了影响NiZn 功率铁氧体材料起始磁导率、饱和磁感应强度及功耗特性的关键因素，为实验中如何控制和改善其磁性能提供重要的理论支撑。然后深入研究了铁氧体微观形貌特征与其磁谱特性和功耗特性的关联，明确在不同工作条件下获得低功耗的微观结构控制要求。之后再系统研究了材料配方组成、制备工艺以及掺杂改性途径等对NiZn铁氧体综合磁性能，尤其是功耗特性的影响，最终成功研制出了磁导率为800和1200的两款低功耗NiZn铁氧体材料，可充分满足小型化功率感性器件应用的需求。