添加Dy元素对钕铁硼速凝片微观组织和磁特性的影响

Effect of Dy additive on microstructure and magnetic properties of rapidly solidified Nd-Fe-B strips

本文讨论了不同含量的Dy元素对速凝条带微观组织的影响,得出Dy的添加量为1—2(at)时条带的微观结构得到最优化,柱状晶生长均匀一致,具有良好的沿c轴取向度.同时,急冷面的细小等轴晶生长区域减少,氢破后相应的磁粉抗氧化性能增强.

Sintered Nd-Fe-B magnets made from strip cast alloys have been studied extensively owing to their strong permanent magnetic properties.Up to now the studies mainly focus on technology parameters of strip casting,including casting temperature,wheel speed and phase transition temperature and so on.However,microstructure and properties of rapidly solidified strips could be influenced by the composition of alloy.In this work,the effects of added Dy element on microstructures and properties of Nd-Fe-B rapidly solidified strips have been investigated.The strips shad a pronounced texture of the tetragonal T1（2141） phase as shown by the prominent（00l） peaks at wheel surface.The alignment coefficient of the strips was the highest when Dy content ranged from 1 to 2at.This is the result of the microstructure of strips being optimized through an appropriate amount of Dy addition.At the same time,the volume fraction of isotropic crystal decreased as Dy content increased.It revealed that the oxidation speed decreased with increasing Dy content.