Effect of bath composition and pulse electrodeposition condition on characteristics and microhardness of cobalt coatings  

镀液组成和脉冲电沉积条件对钴镀层特性和显微硬度的影响（英文）

作　　者：S.MAHDAVI S.R.ALLAHKARAM S.MAHDAVI;S.R.ALLAHKARAM(Research Center for Advanced Materials,Faculty of Materials Engineering,Sahand University of Technology;School of Metallurgy and Materials Engineering,College of Engineering,University of Tehran)

机构地区：[1]Research Center for Advanced Materials,Faculty of Materials Engineering,Sahand University of Technology,5133511996,Tabriz,Iran [2]School of Metallurgy and Materials Engineering,College of Engineering,University of Tehran,Tehran,Iran

出　　处：《Transactions of Nonferrous Metals Society of China》2018年第10期2017-2027,共11页中国有色金属学报（英文版）

摘　　要：Nanocrystalline cobalt coatings were produced from cobalt sulfate based electrolytes by using pulse current electrodeposition technique.The effects of bath composition and electrodeposition condition on current efficiency,morphology,structure and hardness of the coatings were investigated and the optimum deposition condition was determined.It was found that increment of cobalt sulfate concentration and sodium dodecyl sulfate(SDS)concentration in the bath had a negligible effect on microhardness of the coatings,while they were effective on electrodeposition current efficiency.Adding saccharin to electrodeposition bath decreased crystallite size of hexagonal close-packed(hcp)cobalt films and increased their microhardness without significant effect on current efficiency.Smoother and less defective coatings were also obtained from baths containing SDS and saccharin.The results revealed that both the current efficiency and microhardness were changed by variation of peak current density and duty cycle.Besides change of smooth morphology of the coatings to needle-shaped one,crystallite sizes and preferred orientation also varied with increasing the current density and duty cycle.采用脉冲电沉积技术从硫酸钴基电解液中制备纳米晶钴镀层,研究镀液组成和电沉积条件对电流效率以及镀层形貌、结构和硬度的影响,确定最佳沉积条件。研究发现,增大镀液中硫酸钴浓度和十二烷基硫酸钠(SDS)含量对镀层显微硬度的影响可忽略不计,而对电沉积电流效率的影响显著。在电沉积镀液中加入糖精,可使六方密堆结构(hcp)钴薄膜的晶粒尺寸减小,显微硬度提高,而对电流效率无显著影响。在含有SDS和糖精的镀液中获得的镀层表面更光滑,缺陷更少。结果表明,电流效率和显微硬度均随峰值电流密度和占空比的变化而变化,随着电流密度和占空比的增大,表面光滑的镀层变为针状,晶粒尺寸和择优取向也随之改变。

关 键 词：cobalt coating pulse electrodeposition SACCHARIN sodium dodecyl sulfate characterization current efficiency MICROHARDNESS 

分 类 号：TQ153[化学工程—电化学工业]