沉积参数对Ni-Co镀层成分及微观结构影响研究  

Effect of deposition parameters on the composition and microstructure of electrodeposited Ni-Co films

作　　者：王丹[1] 高吉成[1] 张骥群[1] 成艳芳[1] 靳惠明[1] 

机构地区：[1]扬州大学机械工程学院,扬州225127

出　　处：《四川大学学报（自然科学版）》2013年第1期118-124,共7页Journal of Sichuan University(Natural Science Edition)

基　　金：江苏省自然科学基金(07KJD490021)

摘　　要：通过硫酸盐体系脉冲电沉积制备Ni-Co合金镀层,用附有能谱(EDS)的扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X-射线衍射仪(XRD)对沉积过程中CoSO4添加浓度、阴极电流密度及脉冲频率的变化对Ni-Co合金镀层成分及微观结构的影响进行了实验研究,并且测量了不同钴含量镀层的硬度值,分析了镀层硬度变化的微观机理.结果表明,CoSO4添加浓度的增加及脉冲频率的增加,会使镀层中钴含量增加;而阴极电流密度的增大,会使镀层中钴含量降低.增大镀液中CoSO4添加浓度、降低阴极电流密度和提高脉冲频率有利于提高镀层的平整度和致密性,但过高的脉冲频率会使镀层表面由最初的球状晶簇群变为分支针状晶簇群;随着镀液中CoSO4添加浓度的增加,镀层微观结构由面心立方(fcc)结构转变为面心立方和密排六方(fcc+hcp)的混合结构;镀层硬度随着镀层钴含量的增加,先增大后减小.Ni-Co alloy coatings with different compositions and microstructures were electrodeposited employing sulphamate electrolyte. The effects of COSO4 addition in electrolyte, current density and pulse frequency on the composition and microstructure of Ni-Co alloy coatings were investigated systemi- cally by scanning electronic microscopy （SEM） with energy dispersive spectrum （EDS）, transmission e- lectronic microscopy （TEM） and X-ray diffraction （XRD） spectrometer. The microhardness values of the coatings with different Co contents were measured, and the mechanisms of the variation in micro- hardness were studied. The results show that the Co content increases with the increasing COSO4 addi- tion and pulse frequency, but decreases with the increasing current density. The morphology becomes smoother and more compact at high COSO4 addition, high pulse frequency and low current density, but it changes from spherical cluster to a regularly branched acicular structure by increasing pulse frequency to 5000 Hz and beyond. The phase structure of Ni-Co coatings gradually change from fcc into hcp＋fccstructure with the increasing Co content. The microhardness of Ni-Co coatings has a maximum arround 19wt% COSO4 addition in electrolyte.

关 键 词：脉冲电镀 镍钴合金 微观结构 显微硬度 

分 类 号：TQ153.2[化学工程—电化学工业]