晶界添加Ho63.3Fe36.7对NdFeB再生磁体组织与性能的影响

• 作 者: 孙前程 姚青荣 龙乾新 黄伟超 邓健秋 王江 饶光辉 周怀营
• 机 构: 桂林电子科技大学材料科学与工程学院广西信息材料重点实验室,广西桂林541004;中国稀土(广西)金源新材料有限公司,广西贺州542603
• 出 处: 稀有金属材料与工程
• 发表日期: 2021年12期
• 关键词: NdFeB regenerated magnet magnetic property intergranular addition alignment degr

采用一种高效、绿色的物理方法对NdFeB废旧磁体表面进行清理并回收利用.通过晶界添加低熔点Ho63.3Fe367合金制备NdFeB再生磁体.在未添加Ho633Fe367的磁体中,没有足够的富Nd相隔离Nd2Fe14B相,从而导致磁体性能较差;随着Ho63.3Fe367合金的加入,晶界相变得清晰且连续.在质量分数2％Ho63.3Fe36.7添加量下,钕铁硼再生磁体获得最佳磁性能[(BH)max+Hj=1756.07].此时矫顽力增加123 kA/m(约提高9.1％),磁体的最大能积由290.94kJ/m3下降到281.07kJ/m3,而剩磁少量下降.通过对再生磁体显微组织和成分的分析可知,磁体晶界处形成了(Nd,Pr,Ho)2Fe14B壳层,这能够提高磁体的矫顽力.而x射线衍射分析表明,磁体I(006)/I(105)的衍射峰强度比从0.92提高到1.32.这说明磁体取向度提高,可以减弱对剩磁的影响,从而使得再生磁体在保持剩磁的同时提高磁体的矫顽力.“,”A high-efficiency and green physical method was proposed to clean the surface of NdFeB waste magnets for recycling.NdFeB regenerated magnets were fabricated by adding low-melting point Ho63.3Fe36.7 alloy to grain boundaries.Results show that in magnets without Ho63.3Fe36.7,there are insufficient Nd-rich phases to isolate the Nd2Fe14B phase,leading to poor magnet performance.With the addition of Ho63.3Fe36.7 alloy,the grain boundary phases become clear and concatenated.Optimal magnetic energy[(BH)max+Hcj=1756.07]can be obtained by adding 2wt％ Ho63.3Fe36.7 to the magnet.Further,the coercivity increases by 123 kA/m(approximately 9.1％),the maximum magnetic energy product decreases from 290.94 kJ/m3 to 281.07 kJ/m3,and remanence decreases slightly.Through analysis of the microstructure and composition,it can be seen that the (Nd,Pr,Ho)2Fe14B shell layers form at the grain boundary,which enhances the coercivity of the magnet.X-ray diffraction analysis suggests that the diffraction peak intensity ratio of magnet I(006)/I(105) increases from 0.92 to 1.32,which indicates that the alignment degree is improved and the influence on remanence is weakened.Therefore,regenerated magnets can possess improved coercivity while maintaining magnetic remanence.