晶界添加PrNd和Pr_(75)Al_(15)Cu_(10)对细晶无重稀土烧结钕铁硼磁体磁性能和力学性能的影响  

Effect of grain boundaryaddition of PrNd and Pr_(75)Al_(15)Cu_(10)on magnetic and mechanical properties of fine-grained heavy-rare-earth-free sintered Nd-Fe-B magnets

作　　者：彭研硕 李建忠 吴厅兰 金伟洋 周鸿波 刘孝莲 PENG Yanshuo;LI Jianzhong;WU Tinglan;JIN Weiyang;ZHOU Hongbo;LIU Xiaolian(Ningbo Permanent Magnetics Co.,Ltd.,Ningbo 315000,Zhejiang,China;Hangzhou Dianzi University,Hangzhou 310018,Zhejiang,China)

机构地区：[1]宁波永久磁业有限公司,浙江宁波315000 [2]杭州电子科技大学,浙江杭州310018

出　　处：《金属功能材料》2024年第6期184-194,共11页Metallic Functional Materials

基　　金：国家重点研发计划(2021YFB3502803);浙江省自然科学基金(LY24E010003);浙江省博士后科研择优资助项目。

摘　　要：分别采用晶界添加1%(质量分数)Pr_(25)Nd_(75)控氧及气流磨加氧工艺、晶界添加2%(质量分数)Pr_(75)Al_(15)Cu_(10)合金方法,结合细晶工艺制备出了晶粒尺寸为3.5~4.2μm的无重稀土50H烧结钕铁硼磁体。通过对比分析了磁体的磁性能和力学性能后可知,晶界添加1%(质量分数)PrNd控氧磁体矫顽力18.46kOe,抗弯强度为492 MPa,矫顽力与加氧工艺的磁体基本相同,抗弯强度高65MPa。晶界添加2%(质量分数)Pr_(75)Al_(15)Cu_(10)合金的磁体矫顽力达到19.04kOe比添加1%(质量分数)PrNd的控氧磁体高0.58kOe,抗弯强度达到506MPa,比添加1%(质量分数)PrNd磁体高14MPa。分析结果表明,细晶控氧工艺比预氧化工艺磁体中氧含量低134×10^(-6)。晶界添加2%(质量分数)Pr_(75)Al_(15)Cu_(10)使Pr、Cu元素在晶界聚集,使磁体的晶界相分布均匀、连续从而提升了磁体的矫顽力。同时添加2%(质量分数)Pr_(75)Al_(15)Cu_(10)合金有效增加了磁体晶界相比例和优化显微组织,可以有效地阻碍裂纹的传播和扩展,使磁体的抗弯强度得到改善。Fine-grained heavy-rare-earth-free sintered NdFeB magnets were prepared by adding 1%(mass fraction)Pr_(25)Nd_(75)and 2%(mass fraction)Pr_(75)Al_(15)Cu_(10).Furthermore,addition of 1%(mass fraction)PrNd was utilized by oxygen controling and adding oxygen during the jet-milling process.The average grain size of the magnets was 3.5-4.2μm.Magnetic and mechanical properties of the investigated magnets were analyzed and compared.The coercivity of the magnets with 1%PrNd(mass fraction)addition by oxygen controling was 18.46kOe and the bending strength was 492MPa,which was basically the same as the magnets by adding oxygen in coercivity,and 65MPa higher than the magnets by adding oxygen in bending strength.The coercivity of the magnets with addition of 2%(mass fraction)Pr_(75)Al_(15)Cu_(10)reached 19.04kOe,which was 0.58kOe higher than the magnets with addition of 1%PrNd by oxygen controling.The bending strength of the magnets with addition of 2%(mass fraction)Pr_(75)Al_(15)Cu_(10)reached 506MPa,which was 14MPa higher than the magnets with addition of 1%(mass fraction)PrNd by oxygen controling.The results showed that the oxygen content in the magnets with fine-grained controlled oxygen process was 134×10^(-6) lower than the magnets with oxygen added during the jet-milling process.Pr and Cu elements were congregated the grain boundary via the addition of 2%(mass fraction)Pr_(75)Al_(15)Cu_(10),which resulted in uniform and continuous distribution of the grain boundary.The optimized grain boundary improved the coercivity of the magnets.Meanwhile,the addition of 2%(mass fraction)Pr_(75)Al_(15)Cu_(10)alloy effectively enhanced the proportion and distribution of the grain boundary phase,which could effectively hinder the propagation and expansion of cracks,thereby improving the bending strength of the magnets.

关 键 词：烧结钕铁硼磁体 晶界添加 晶粒细化 矫顽力 抗弯强度 

分 类 号：TM2[一般工业技术—材料科学与工程]