Simultaneous increase in remanence and coercivity during grain refining of Nd-Fe-B deformed magnets

作     者：Fengqing Wang Kanghua Chen Juan Du Jian Zhang Fengqing Wang;Kanghua Chen;Juan Du;Jian Zhang

作者机构：CAS Key Laboratory of Magnetic Materials and DevicesNingbo Institute of Materials Technology and EngineeringChinese Academy of Sciences(CAS)Ningbo 315201China Zhejiang Province Key Laboratory of Magnetic Materials and Application TechnologyNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China State Key Laboratory for Powder MetallurgyCentral South UniversityChangsha 410083China Institute of MaterialsShanghai UniversityShanghai 200444China 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2022年第40卷第11期

页      面：1763-1771,I0004页

核心收录：

学科分类：080801[工学-电机与电器] 0808[工学-电气工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：Project supported by the National Natural Science Foundation of China(51901237,51901234,51771220) High-tech Tacking Project from Baotou Rare Earth Research and Development Center,Chinese Academy of Sciences(GZR 2018002) Zhejiang Provincial Natural Science Foundation(LD19E010001) 

主　　题：NdFeB magnets Grain size Plastic deformation Texture Coercivity Rare earths 

摘      要：To explore the feasibility of deep grain-size refinement in overcoming the problem of traditional B-Htrade-off in bulk permanent magnets,the effect of deformation temperature on the texture strength,grain refining,and magnetic properties of slow-deformed Nd-Fe-B magnets was systematically *** a result,strong textures with gradual grain refining from conventionally large size of D=650 nm to small nanoscale size of D=53 nm(Ddenotes the lateral size of the aligned plate-like grains)are observed as the temperature reduces from T=650℃to T=450℃.Moreover,magnetic observations show a simultaneous increase in remanence and coercivity as the grain refines from D=650 nm to D=127 *** increase in coercivity results from the grain size refinement as well as the smaller aspect ratio of the plate-like grains,and the increase in remanence results from the improved texture *** compared with the D=650 nm magnets,the simultaneous increase in remanence and coercivity leads to optimum enhancements of 57%in coercivity,10%in remanence,and 25%in energy product,which demonstrate the feasibility of near-nano scale grain refinement in overcoming the traditional B-Htrade-off for improved(BH)*** failure of higher coercivities in the D≤80 nm magnets is closely related with the defect effects of the grain *** explaining the grain refining and texture changing behavior were also discussed.