摘要
在工业生产线上制备24.5Nd-8Pr-0.55Nb-0.20Cu-0.65Al-1.15B-Fe+x%(质量分数)Dy2O3烧结磁体,分析了磁体密度、显微组织、取向度、磁性能以及抗弯强度与Dy2O3添加数量的关系。结果表明,随着x由0增加至0.8,2.4,磁体密度由7.470 g.cm-3略微上升至7.481 g.cm-3,而后明显下降至7.369 g.cm-3;平均晶粒尺寸由8.6μm持续增大至9.3,10.8μm,且晶粒尺寸分布不均匀;I006/I105比值则由1.305增大至1.394,1.688,磁体取向度明显提高。当x由0增加至1.2,2.4时,剩磁由1.244 T近似线性地降低到1.218,1.187 T;内禀矫顽力从1124.8 kA.m-1迅速提高到1307.8 kA.m-1,而后缓慢上升至1381.8 kA.m-1;磁体抗弯强度则从325 MPa缓慢降低至319 MPa,而后迅速下降至231 MPa左右。添加Dy2O3使富钕液相的流动性及其对主相颗粒的润湿性变差,不利于富钕液相的均匀分布,阻碍磁体烧结致密化过程,促进烧结过程晶粒长大。适量添加Dy2O3,使内禀矫顽力显著提高,剩磁出现一定程度的下降;当Dy2O3添加数量比较大时,其提高内禀矫顽力的效应明显减小,同时磁体抗弯强度大幅度降低。
24.5 Nd-8 Pr-0.55 Nb-0.20 Cu-0.65 Al-1.15 B-Fe ＋ x% （ mass fraction ） Dy2O3 sintered magnets were manufactured on the mass-production line. The dependence of density, microstructure, orientation degree, magnetic properties and bending strength of the magnets on the amount of Dy2O3 addition was investigated. According to the experimental results, as x increased from 0 to 0.8, 2.4, the density slightly rose from 7. 470 to 7. 481 g·cm^-3, and then obviously declined to 7. 369 g·cm^-3 ; the average grain size continuously increased from 8.6 to 9.3 μm, 10.8 μm and the grain size distribution became broader; and the value of I006/I105 increased from 1. 305 to 1. 394, 1. 688 and the orientation degree was remarkably improved. When x increased from 0 to 1.2, 2.4, the remanence approximately linearly decreased from 1. 244 to 1. 218 T, 1. 187 T; the intrinsic coercivity was enhanced first rapidly from 1124.8 to 1307.8 kA·m^-1, and then slowly to 1381.8 kA·m^-1; and the bending strength went down first slowly from 325 to 319 MPa, and then rapidly to about 231 MPa. Dy2O3 addition led to lower mobility, worse wettability and more inhomogeneous distribution of the Nd-rich liquid phase, which impeded densification and accelerated grain growth during the sintering process. Appropriate amounts of Dy2O3 addition improved markedly the intrinsic coercivity and reduced the remanence to a certain extent; when the amount of Dy2O3 addition was too large, the effect for Dy2O3 addition to improve the intrinsic coercivity weakened and the bending strength started to apparently decrease.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2012年第6期904-909,共6页
Chinese Journal of Rare Metals
基金
国家自然科学基金资助项目(50871056)
关键词
钕铁硼磁体
Dy2O3
烧结行为
磁性能
力学性能
Nd-Fe-B magnets
Dy2O3
sintering behavior
magnetic properties
mechanical properties
