Anisotropic corrosion behavior of sintered(Ce_(0.15)Nd_(0.85))_(30)Fe_(bal)B permanent magnets

作     者：Xiaoning Shi Minggang Zhu Dong Zhou Zheng Jing Meiling Zhang Wei Li 

作者机构：Division of Functional Material Central Iron & Steel Research Institute 

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

年 卷 期：2019年第37卷第3期

页      面：287-291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 National Natural Science Foundation of China(51571064) National Basic Research Program of China(2014CB643701) Plan of National Key Research and Development(2016YFB0700903) 

主　　题：Sintered Nd-Fe-B Ce Dual main phase Anisotropic Electrochemistry Corrosion 

摘      要：In this work, the corrosion behavior of the surface parallel to the oriented c-axis(c‖) and perpendicular to c-axis(c⊥)in the(Ce_(0.15)Nd_(0.85))_(30)Fe_(bal)B dual main phase magnet was studied. With the addition of Ce,the volume fraction of RE-rich phase shown in the backscattered electron(BSE) images is basically approximate on the two surfaces. The free corrosion potential(E_(corr)) of the c‖ surface is more negative,which shows the worse corrosion resistance from the perspective of thermodynamics. While the reaction kinetics parameters with the smaller free corrosion current(i_(corr)) and the larger transfer resistance(R_(ct)) react the opposite conclusion in 3.5 wt% NaCl solution. Moreover, the c‖ surface performs smaller ions concentration of corrosion product and less damaged corrosion morphology compared to c⊥ surface after the free corrosion. The inconformity is not affected by the RE-rich phase, but by the anisotropy of the grains that the c‖ surface has larger density of the atoms and the lower ratio of(Nd, Ce)/Fe.