Enhancement of corrosion resistance in sintered Nd-Fe-B permanent magnet doping with different CuZn_

• 作 者: Zhuang Wang Wei-Qiang Liu Dong-Tao Zhang Ming Yue Xiu-Lian Huang Xu-Liang Li
• 机 构: College of Materials Science and Engineering, Beijing University of Technology,The Key Laboratory of
• 出 处: Rare Metals
• 发表日期: 2017年10期
• 关键词: doping magnet permanent sintered coercivity systematically powders distilled kin

Nd-Fe-B permanent magnets doped with CuZn_5 powders were prepared via conventional sintered method. The effects of CuZn_5 contents on magnetic properties and corrosion resistance of the magnets were systematically studied. It shows that the remanence,coercivity, and maximum energy product decrease gradually with the increase in CuZn_5 doping content. The magnet’s corrosion kinetics in autoclaves environment and its electrochemical properties in electrolytes were also examined. It is interesting to see that the weight loss of3.5 wt% and 4.5 wt% CuZn5 powders doping magnets is only 1 and 0 mg·cm~(-2) after autoclaves test at 121℃,2 ×10~5 Pa for 500 h, respectively, which is much lower than that of the magnets without CuZn_5 doping. Electrochemical results show that the CuZn_5 powders doping magnets display more positive corrosion potential(E_(corr))and lower corrosion current density(I_(corr)) than those of the original magnets without CuZn_5 doping in sulphuric acid electrolyte and distilled water. It is, therefore, concluded that doping CuZn_5 powders is a promising way to enhance the corrosion resistance of sintered Nd-Fe-B magnets.

Nd-Fe-B permanent magnets doped with CuZn_5 powders were prepared via conventional sintering method. The effects of CuZn_5 contents on magnetic properties and corrosion resistance of the magnets were systematically studied. It shows that the remanence, coercivity, and maximum energy product with the increase in CuZn_5 doping content. The magnet’s corrosion kinetics in autoclaves environment and its electrochemical properties in electrolytes were also examined. It is interesting to see that the weight loss of 3.5 wt% and 4.5 wt% CuZn5 powders doping magnets is only 1 and 0 mg · cm -2 after autoclaves test at 121 ℃, 2 × 10 ~ 5 Pa for 500 h, respectively, which is much lower than that of the magnets without CuZn_5 doping. Electrochemical results show that the CuZn_5 powders doping more negative corrosion potential (E_ (corr)) and lower corrosion current density (I_ (corr)) than those of the original magnets without CuZn_5 doping in sulphuric acid electrolyte and distilled water. It is, therefore, said that doping CuZn_5 powders is a promising way to enhance the corrosion resistance of sintered Nd-Fe-B magnets.