Improvement of corrosion resistance in Nd–Fe–B magnets through grain boundaries restructuring
Improvement of corrosion resistance in Nd–Fe–B magnets through grain boundaries restructuring
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DOI：
10.1016/j.matlet.2012.01.100
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发表时间：
2012-05
影响因子：
3
通讯作者：
J. Ni;T. Ma;M. Yan
中科院分区：
文献类型：
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作者：
J. Ni;T. Ma;M. Yan
Nd-Fe-B烧结磁体由于Nd 2Fe 14 B基体与富Nd晶间相之间存在较大的电化学电位差而表现出较差的耐腐蚀性。本文提出了一种提高（Pr，Nd）-Fe-B烧结磁体在潮湿和酸性环境中耐蚀性的新方法，即用（Pr，Nd）6 Fe 13 Cu相代替富（Pr，Nd）晶间相，从而显著降低电化学电位差。经96 h热/湿暴露后，重构磁体的质量损失小于1.0mg/cm ~ 2。在0.005M H2SO 4溶液中的耐腐蚀性也可以显著提高。此外，磁体仍具有优异的磁性能，最大磁能积（BH）max为~ 384 kJ/m3，表明晶界重组是制备耐腐蚀Nd-Fe-B烧结磁体的一种有竞争力的方法。
Nd–Fe–B sintered magnets exhibit poor corrosion resistance due to the large electrochemical potential difference between the Nd2Fe14B matrix and the Nd-rich intergranular phase. This letter presents a new approach to improve corrosion resistance of (Pr,Nd)–Fe–B sintered magnets in both humid atmosphere and acidic environment through replacing the (Pr,Nd)-rich intergranular phase by a (Pr,Nd)6Fe13Cu one, which can reduce significantly the electrochemical potential difference. Mass loss for the restructured magnets is less than 1.0mg/cm2after exposure to heat/humid atmosphere for 96h. Corrosion resistance in 0.005M H2SO4solutions can also be significantly improved. In addition, the magnets still possess outstanding magnetic properties, with a maximum energy product (BH)maxof ~384kJ/m3, demonstrating that the grain boundaries restructuring is a competitive method to fabricate corrosion-resistant Nd–Fe–B sintered magnets.