微量Ti元素掺杂烧结钕铁硼相变及微观结构调控研究

Study on Phase and Microstructure Transformation of Sintered Nd-Fe-B Magnet with Trace Ti Element Doping

本研究采用粉末冶金工艺制备了微量Ti元素掺杂的烧结钕铁硼永磁材料,研究了微量高熔点元素掺杂对材料物相构成、显微组织结构及性能的影响。结果表明:Ti元素在速凝合金中相对均匀的在晶界富稀土相分布,部分Ti元素甚至进入主相内部,而在烧结磁体中Ti元素以TiB;沉淀相形式存在于晶界富稀土相中,通过Ti元素掺杂可以有效调控富稀土相的物相组成及分布,TiB;沉淀相可以抑制主相晶粒在烧结过程中的异常长大,获得主相晶粒尺度均匀适中、富稀土相连续分布的烧结钕铁硼磁体,显微组织结构的优化带来磁体性能的显著提升。

Sintered Nd-Fe-B magnets with trace Ti element doping were prepared by powder metallurgy method in this work.The effect of high-melting-point element doping on phase and microstructure transformation of the magnets was investigated.Results show that Ti element is relatively well-distributed in the grain boundary rare earth rich phase in the casting strips with a small amount of Ti elements entering the main phase.In the sintered magnet,Ti mainly exists at the grain boundary in the form of TiB;precipitation phase.The composition and distribution of rare earth rich phase can be effectively controlled and the abnormal growth of main phase grains during the sintering process was inhibited.Significant coercivity enhancement can be achieved for the sintered Nd-Fe-B magnet with uniform and moderate main grains and continuous distribution of rare earth rich phase.