预浸对烧结钕铁硼HEDP电镀铜的影响  

Effect of pre-dipping on copper electroplating in a HEDP-based electrolyte for sintered NdFeB magnet

作　　者：刘志恒 王春霞[1] 田礼熙 谌宏 何佳俊 张霖飞 LIU Zhiheng;WANG Chunxia;TIAN Lixi;CHEN Hong;HE Jiajun;ZHANG Linfei(School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《电镀与涂饰》2024年第1期24-34,共11页Electroplating & Finishing

摘　　要：[目的]烧结钕铁硼(Nd Fe B)的电镀前处理技术还不够成熟,开发适宜的前处理工艺极其重要。[方法]在电镀铜前,先采用以羟基乙叉二膦酸(HEDP)为主配位剂的溶液对NdFeB进行预浸。预浸液组成和工艺条件为:HEDP 20~30 g/L,氢氧化钾20~25 g/L,碳酸钾10~15 g/L,葡萄糖酸钾1~2 g/L,乙酸0.5~1.0 g/L,室温,时间60 s。通过电化学测试对比了Nd Fe B基体有无预浸处理时,铜在其表面的电沉积行为,并通过金相显微镜、扫描电镜、能谱仪和荧光光谱测厚仪,对比了有无预浸处理的Nd FeB基体表面Cu镀层的宏观和微观表面形貌、截面形貌、元素分布及厚度分布均匀性。[结果]Nd Fe B基体预浸后表面被活化,静态电位降低。预浸液能够填满基体表面的孔隙并形成一层水薄膜,在后续电镀铜时保护基体不被腐蚀。预浸处理的Nd Fe B基体表面所得Cu镀层均匀、致密,不易氧化发黑,结合力和耐蚀性较好。[结论]对烧结钕铁硼进行预浸处理,能够保证其在后续电镀铜过程不被腐蚀,提高Cu镀层的综合性能。[Introduction]The pretreatment of sintered neodymium-iron-boron(NdFeB)magnet before electroplating is not mature enough.It is very important to develop a suitable pretreatment process for sintered NdFeB.[Method]The sintered NdFeB was pre-dipped in a solution with 1-hydroxyethylidene-1,1-diphosphonic acid(HEDP)as main complexing agent prior to being electroplated with copper.The solution composition and operation conditions of pre-dipping are as follows:HEDP 20-30 g/L,potassium hydroxide 20-25 g/L,potassium carbonate 10-15 g/L,potassium gluconate 1-2 g/L,acetic acid 0.5-1.0 g/L,room temperature,and time 60 s.The electrodeposition behaviors of copper on the surface of NdFeB with and without pre-dipping were compared by electrochemical test.The macroscopic and microscopic surface morphology,cross-section morphology,element distribution,and thickness uniformity of Cu coatings electroplated on NdFeB with and without pre-dipping were compared by using metallurgical microscope,scanning electron microscope(SEM),energy-dispersive spectrometer(EDS),and X-ray fluorescence(XRF)coating thickness gauge.[Result]The NdFeB was activated after being pre-dipped with a decrease in static potential.The micropores on the surface of NdFeB could be filled by the pre-dipping solution,and an aqueous film was formed,which would prevent the magnet from being corroded during the subsequent copper electroplating.The Cu coating electroplated on the pre-dipped NdFeB surface was uniform and compact,not easy to oxidize and blacken,and featured good adhesion and corrosion resistance.[Conclusion]The sintered NdFeB won’t be corroded by electrolyte during copper electroplating if being pre-dipped in a HEDP-based solution,and the comprehensive performance of Cu coating electroplated subsequently will be improved.

关 键 词：烧结钕铁硼永磁体 无氰电镀铜 预浸 孔隙率 结合力 均镀能力 耐蚀性 

分 类 号：TQ153.14[化学工程—电化学工业]