烧结含镝钕铁硼永磁体时效后的微观组织分析

The Microstructure Analysis of Sintered Dysprosium-doped NdFeB Permanent Magnet after Aging

本文采用场发射扫描电镜、能谱仪和金相显微镜等研究了时效对烧结含镝钕铁硼永磁体的相组成和显微组织的影响。实验结果表明,烧结含镝钕铁硼永磁体经一级、二级时效后,组成相有Nd2Fe14B主晶相和在晶界交隅处析出的较多富钕相及少量富硼相。时效后Nd2Fe14B主晶相的晶界较烧结态变得清晰、平直,这是其内禀矫顽力明显增高的主要原因。

This paper dealt with the effect of aging on the phase constitutes and microstructure of the sin tered dysprosiumdoped NdFeB permanent magnet by means of a field emission scanning electronic micros copy, energy spectrometer and metallographic microscopy. The experimental results showed that after the first and second stages of the aging, the phase constitutes were the main crystal phase of Nd2Fe14B, more phase of rich neodymium and a few phase of rich boron which often precipitated in the corner of grain boundary. The grain boundary of the dysprosiumdoped NdFeB permanent magnet after the aging showed more clear, flat and straight than that of the sintered one and it is the a main cause on their inner coercive force increased obviously.