Effects of the wheel speeds v and disproportionation time during the SC-HDDR process on the properties of Nd-Fe-B magnetic powders are investigated.It is found that the remanence Br,coercivity Hcj and energy products(BH)max of magnetic powders all first increase to the maximum at v=3 m/s,and then decrease with enhancing v.This is attributed to the fact that the SC alloy flakes prepared by the wheel speed of 3 m/s display the optimized microstructure.This optimized SC alloy flakes without homogenizing treatment which carried out a short duration disproportionation treatment can prepare the evidently anisotropic powders.With prolonging disproportionation time,the alignment degree of anisotropy of magnetic powders gradually decreases.This is due to the fact that a short duration disproportionation reaction is beneficial to the disproportionated microstructure displaying the lamella crystals,and the lamella disproportionated microstructure is helpful to the formation of anisotropy.Our results confirm that the anisotropic HDDR Nd-Fe-B magnetic powders prepared directly from the SC alloy flakes without homogenizing treatment can be obtained.
LIU Min1,3,HAN BaiPing2,3,HAN GuangBing3 & GAO RuWei3 1 Department of Electronic Science,Huizhou University,Huizhou 516007,China
用在谷物边界的建议不同 anisotropy 表情 K 1′(r) 和 K 1″(r) ，我们调查效果内部平均 anisotropy 〈K 1〉 上的小粒的阶段(IP )谷物边界和 coercivity H HDDR (加氢， disproportionation，解吸附作用和再结合) 的 c Nd-Fe-B 结合了磁铁。当 IP 的厚度 d 是零时，结果显示那， 〈K 1〉并且 H c 基于 K 1″(r) 基于 K 1′(r) 等于相应的。当 d 拿非零价值时， 〈K 1〉并且 H 分别地， c 与增加 d 更快基于 K 1″(r) 掉落并且升起。当 d 是 1 nm，结构缺点厚度 r 0 接近域墙(∼4 nm ) 的厚度时，计算 coercivity 与 avaiable 一致很好试验性的数据。
