Watts型镀钴体系电沉积工艺优化  

Optimization of cobalt electrodeposition process in Watts bath

作　　者：卓健飞 何雨波 汪镇涛 谢新 刘亚雄 张志新 王帅星[2] 杜楠[2] Zhuo Jianfei;He Yubo;Wang Zhentao;Xie Xin;Liu Yaxiong;Zhang Zhixin;Wang Shuaixing;Du Nan(AECC Changjiang Engine Company Co.Ltd.,Yueyang 414001,China;School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]中国航发长江动力有限公司,湖南岳阳414001 [2]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《电镀与精饰》2023年第3期52-59,共8页Plating & Finishing

基　　金：中国航空发动机集团产学研合作项目(HFZL2020CXY026)。

摘　　要：针对Watts型镀钴工艺,系统研究了Co^(2+)/H3BO3摩尔比、表面活性剂、pH、温度、电流密度等参数对镀层沉积速度、硬度及微观结构的影响规律,获得了较佳的Watts型镀钴工艺方案。结果表明:适当增加Co^(2+)含量可以加快镀层沉积速度,但过高Co盐会使阴极极化度减小、镀层结晶粗大;Co^(2+)/H3BO3摩尔比在1.5时,Co^(2+)的沉积电位较负、结晶更为细致。电流密度对镀层沉积速度影响最大,溶液pH值则显著影响镀层显微硬度;提高电流密度,镀层沉积加快,但镀层容易粗糙,电流密度可选择4 A/dm^(2);升高镀液pH值有助于获得细致镀层,但pH>5后镀液易出现沉淀;温度在40℃时镀层沉积速度和硬度均较佳。在优化的Watts型镀钴体系下所得镀层呈灰白色,晶粒呈棱片状,表面平整光滑,镀层硬度为320 HV,沉积速度为22μm/h。GH4169合金表面施镀60μm厚的钴镀层,可以显著改善其耐磨性。The effects of Co^(2+)/H3BO3molar ratio,surfactant,pH,temperature and current density on the deposition rate,hardness and microstructure of the coating were systematically studied,and a better Watts type cobalt plating electroplating process was obtained.The results show that proper increase of Co^(2+)content can increase the deposition rate of coating,but too high content of cobalt salt may reduce the cathode polarization and make coarse crystal grains.The deposition potential of Co^(2+)is more negative and the coating grains are finer when the molar ratio of Co^(2+)/H3BO3is 1.5.The current density has the greatest influence on the deposition rate of coating,but pH value of the solution significantly affects the coating hardness.If the current density is increased,the deposition of the coating is accelerat‐ed,but the coating is easy to be rough,and the current density can be selected as 4 A/dm^(2).Increasing pH value of the bath helps to obtain a fine coating,but the bath is prone to precipitation when pH>5.Both the deposition rate and hardness of the coating are better when the temperature is 40℃.Under the optimized Watts cobalt plating system,the obtained coating is smooth and gray-white,the grains are prismatic,the hardness of the coating is 320HV,and the deposition rate is 22μm/h.The wear resistance of GH4169 alloy can be significantly improved by applying cobalt coating with the thickness of 60μm.

关 键 词：钴 电沉积 Watts型 工艺参数 镀层硬度 

分 类 号：TG174.451[金属学及工艺—金属表面处理]