Nd-Fe-B粉末颗粒间的磁团聚现象及有限元模拟计算  

Magnetic agglomeration interaction among particles of Nd-Fe-B powders and its finite element calculation

作　　者：何叶青 周寿增[2] 宋琪 白山 胡伯平 

机构地区：[1]北京中科三环高技术股份有限公司,北京100080 [2]北京科技大学新金属材料国家重点实验室,北京100083

出　　处：《功能材料》2002年第2期154-156,共3页Journal of Functional Materials

基　　金：国家自然科学基金资助项目 (698780 1 1 )

摘　　要：用扫描电镜 (SEM )观察了Nd Fe B磁粉颗粒之间的磁团聚现象。对呈自然松散状态的Nd Fe B磁粉的磁化曲线测量结果表明 ,磁团聚现象是造成Nd Fe B磁粉难以充分取向的重要原因。用有限元数值分析方法对Nd Fe B磁粉颗粒之间的磁团聚相互作用进行了模拟计算。结果表明 ,随着Nd Fe B粉末颗粒间距的减小 ,颗粒之间的磁团聚作用力明显增大。当Nd Fe B粉末中存在α Fe时 ,颗粒之间的磁团聚作用力明显高于无α Fe时的磁团聚力。由于大部分有效取向外磁场被磁团聚效应抵消了 ,用通常的取向外磁场 (≤ 2 .0T)难以使Nd Fe B磁粉充分取向。Strong agglomeration interaction between Nd Fe B powders was observed by SEM. It is shown by magnetizing measurements that the natural loose powders can not be saturated even the applied field reaches 1.7T. Finite element method was applied for calculation of the magnetic agglomeration interaction between Nd Fe B powders. It is indicated that the magnetic agglomeration interaction may increase greatly if the gap of the particles decreases as well as α Fe particles exist in Nd Fe B powders, and this may do severe damage to the aligning of the powders. During pressing, a great part of the applied field is balanced by the agglomeration interaction. And a static magnetic field of ≤2.0T can not saturate even the loosely fed powders.

关 键 词：ND-FE-B粉末 磁团聚 有限元 磁场取向 永磁材料 

分 类 号：TM273[一般工业技术—材料科学与工程]