摘要
以烧结Nd-Fe-B磁体为基,复合添加了Cu,Co和重稀土Dy,成功制备了具有优良温度稳定性的磁体,磁体最高使用温度T_(w)≈210℃,剩磁温度系数α=-0.053%·℃^(-1)。研究发现,所制备磁体中存在着大量块状富稀土晶界相,而严重缺乏薄层富稀土晶界相,即使经过二级回火,薄层富稀土晶界相数量也没有明显增加。在块状富稀土晶界相中有贫Co相和富Co相同时存在的现象。TEM观察发现在富Co相中有RE_(2)(Fe,Co)_(17)相的存在,这不利于矫顽力的提升。研究表明:晶界处Cu和Co是对立分布的,经过合理的回火工艺后,Cu在晶界的分布更为均匀,Co则主要分布在晶界角落。此外,在一级回火水淬态磁体中的富Co相区域内,发现了RE(Fe,Co)_(2)Laves相。
In this paper,based on sintered Nd-Fe-B magnet,Cu,Co and heavy rare earth Dy were added.The magnet with excellent temperature stability was successfully prepared.The maximum service temperature of the magnet is T_(w)≈210℃and the remanence temperature coefficient isα=-0.053%·℃^(-1).It is found that there are a large number of bulk-like RE-rich grain boundary phases in the magnets,but there is a serious lack of thin RE-rich grain boundary phases.Even after secondary annealing,the number of thin RE-rich grain boundary phases does not increase significantly.In the bulk-like RE-rich grain boundary phase,there exists the Co-lean phase and the Co-rich phase.TEM observation shows that there is RE_(2)(Fe,Co)_(17)phase in the Co-rich phase,which is negative to the improvement of coercivity.The results show that Cu and Co are oppositely distributed at the grain boundary.After reasonable tempering process,the distribution of Cu at the grain boundary is more uniform,while Co is mainly distributed at the corner of the grain boundary.In addition,RE(Fe,Co)_(2)Laves phase was found in the Co-rich phase region of the 1stannealing water quenched sample.
作者
张家滕
徐吉元
胡成林
孟睿阳
董生智
Zhang Jiateng;Xu Jiyuan;Hu Chenglin;Meng Ruiyang;Dong Shengzhi(Division of Functional Materials,Central Iron&Steel Research Institute,Beijing 100081,China;Beijing Keeven Aviation Instrument Co.,Ltd.,Beijing 102402,China)
出处
《中国稀土学报》
EI
CAS
CSCD
北大核心
2022年第2期235-243,共9页
Journal of the Chinese Society of Rare Earths
基金
国家重点研发项目(2021YFB3502900)资助。
