钕铁硼磁体表面双向脉冲电沉积Ni-Cr合金镀层工艺及耐腐蚀性能  

Bidirectional pulsed electrodeposition of Ni-Cr alloy coating process on NdFeB magnets surfaces and corrosion resistance

作　　者：杨牧南 罗三根[2] 邹雅茹 余黎明 YANG Munan;LUO Sangen;ZOU Yaru;YU Liming(Department Materials Science and Engineering,Tianjin University,Tianjin 300000,China;Institute of Rare Earth,Jiangxi University of Science and Technology,Ganzhou 341000,China;National Rare Earth Functional Material Innovation Center&Guorui Scientific Innovation Rare Earth Functional Materials Co.,Ltd.,Ganzhou 341000,China)

机构地区：[1]天津大学材料科学与工程学院,天津300072 [2]江西理工大学稀土学院,赣州341000 [3]国瑞科创稀土功能材料(赣州)有限公司,赣州341000

出　　处：《江西冶金》2024年第4期246-256,共11页Jiangxi Metallurgy

基　　金：国家“十四五”重点研发计划项目(2022YFB3505400)。

摘　　要：钕铁硼(NdFeB)磁体材料在新能源汽车、风力发电等领域广泛应用。但是,磁体易被腐蚀,不利于应用产品的稳定性。本研究采用双向脉冲电沉积技术,考察了不同的脉冲参数(pH值、电流密度、正向占空比、Cr盐浓度)对Ni基镀层耐腐蚀性能和微观结构的影响。结果表明,在pH=4.5、电流密度为0.20 A/cm^(2)、正向占空比为60%、Cr盐含量为25 g/L的条件下,制备的Ni-Cr合金镀层具有优异的表面质量和良好的耐腐蚀性能,其电核转移电阻(R_(ct))值显著增至36990Ω·cm^(2),自腐蚀电位降至-707 mV,腐蚀电流密度仅为1.04×10^(-8)A/cm^(2)。本研究为提升NdFeB磁体的耐腐蚀性能提供了一种有效的方法及理论依据。Neodymium-iron-boron(NdFeB)magnets are widely used in new energy vehicles,wind power generation and other fields.However,the magnets are easily corroded,which is detrimental to the stability of the applied products.In this study,bi-directional pulse electrodeposition technology was employed to investigate the effects of different pulse parameters(pH value,current density,duty cycle of the forward pulse,and Cr salt concentration)on the corrosion resistance and microstructure of Ni-based coatings.The results showed that under the conditions of pH=4.5,current density of 0.20 A/cm^(2),forward duty cycle of 60%,and Cr salt concentration of 25 g/L,the prepared Ni-Cr alloy coating had excellent surface quality and good corrosion resistance.Its Rct value significantly increased to 36990Ω∙cm^(2),the self-corrosion potential dropped to‒707 mV,and the corrosion current density was only 1.04×10^(‒8)A/cm^(2).This study provides an effective method and theoretical basis for enhancing the corrosion resistance of NdFeB magnets.

关 键 词：钕铁硼磁体 双向脉冲电沉积 工艺参数 耐腐蚀性能 

分 类 号：TG174[金属学及工艺—金属表面处理]