Microstructure evolution and coercivity mechanism of hydrogenation-disproportionation-desorption-recombination(HDDR) treated Nd-Fe-B strip cast alloys

作     者：Bin Ma Xiaoqian Bao Aizhi Sun Jiheng Li Xuexu Gao Bin Ma;Xiaoqian Bao;Aizhi Sun;Jiheng Li;Xuexu Gao

作者机构：State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China 

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

年 卷 期：2022年第40卷第5期

页      面：792-799,I0005页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：Project supported by the State Key Laboratory for Advanced Metals and Materials(2019Z-14) 

主　　题：Nd-Fe-B strip Cast HDDR treatmemt Microstructure evolution Coercivity mechanism Three-dimensional atom probe Rare earths 

摘      要：In this paper,we systematically investigated the microstructure evolution and coercivity mechanism of hydrogenation-disproportionation-desorption-recombination(HDDR)treated Nd-Fe-B strip cast alloys by transmission electron microscopy(TEM)and three-dimensional atom probe(3 DAP)*** rodlike NdH_(2+x) phases with diameters of 10-20 nm are embedded intoα-Fe matrix,which hereditarily leads to textured grains in HDDR *** migration of NdH_(2+x) from Nd-rich region toα-Fe matrix during hydrogen absorption process contributes to the uniform redistribution of Nd-rich phases after HDDR treatment The HDDR alloy with single domain grain sizes of 200-300 nm exhibits relatively low coercivity of 1.01 T that arises from pinning magnetic domain *** weak c-axis orientation of HDDR alloy results in a lower reverse magnetic field(coercivity)to reduce remanence to ***,the direct contact of Nd_(2)Fe_(14)B grains and the high concentration of ferromagnetic elements(Fe content≈66.06 at%,Co content≈0.91 at%)in Nd-rich grain boundary layer lead to strong magnetostatic coupling effect among Nd_(2) Fe_(14)B *** nano-sized a-Fe inside Nd_(2) Fe_(14)B matrix makes the magnetization reversal easily and decreases the coercivity of HDDR alloy.