高矫顽力无重稀土钕铁硼磁体Nd6Fe13Ga晶界设计及性能调控机制研究

无重稀土钕铁硼永磁材料矫顽力低的问题限制了其在电动汽车、风力发电等高温环境中的应用。研究表明，Ga掺杂形成Nd6Fe13Ga晶界相可有效提高钕铁硼磁体的矫顽力。但是，钕铁硼合金中难以形成完整均匀的非磁性Nd6Fe13Ga晶界相，是导致磁体矫顽力与理论预测值仍有较大差距的关键。基于前期的研究，本项目拟通过Nd6Fe13Ga晶界重构设计，调控晶界理化特性，系统研究其分布形态与磁性研究对矫顽力的作用规律及机理。深入分析重构晶界相磁畴结构、界面结合方式，揭示其对主相晶粒间交换耦合的作用机理，结合微磁学模拟研究重构晶界相对温度稳定性的作用规律，优化关键制备工艺，获得均匀完整Nd6Fe13Ga全新晶界相构筑最优方案，最终实现高矫顽力无重稀土永磁制备。本项目的完成将解决无重稀土永磁矫顽力低的问题，同时降低磁体成本，突破无重稀土钕铁硼永磁在高温环境的应用瓶颈，具有重要的理论意义和应用价值。

The low coercivity of Dy-free NdFeB permanent magnet material limits the application in the fields of electric vehicles and wind power generation. The formation of Nd6Fe13Ga grain boundary phase can effectively improve the coercivity of Ga-doped NdFeB magnets. However, it is difficult to form a complete and uniform nonferromagnetic Nd6Fe13Ga grain boundary phase in NdFeB alloy, which is the key to the large gap between the coercivity of the magnet and the theoretical value. Based on the previous research, Dy-free NdFeB permanent magnets with high coercivity are prepared through the reconstruction design and regulation of the grain boundary phase. Specifically, by designing the Nd6Fe13Ga grain boundary phase, the physical and chemical properties of the grain boundary are adjusted, and the mechanism of its distribution and magnetic research on the coercivity is discussed. Further by analyzing the magnetic domain structure and interface of the reconstructed grain boundary phase, the mechanism of exchange coupling between the main phase grains is revealed. After optimizing the key preparation process, the best structure of the new Nd6Fe13Ga grain boundary phase is obtained. Finally, Dy-free NdFeB permanent magnets with high coercivity are achieved. This project aims to solving the problem of low coercivity of Dy-free NdFeB permanent magnets. The present proposal will provide important theoretical and technical basis to achieve high magnetic performance in the Dy-free NdFeB permanent magnets, which may promote their engineering applications.