恒电位脉冲电沉积高锡青铜耐蚀镀层工艺研究  

Preparation of High-tin Bronze Corrosion-resistant Coating by Potentiostatic Pulse Electrodeposition

作　　者：包任 周根树[1] 李宏伟 BAO Ren;ZHOU Genshu;LI Hongwei(State Key Laboratory for Mechanical Behavior of Materials,Xi'an Jiaotong University,Xi'an 710049,China;Equipment Maintenance Center,Shenhua Shenmu Coal Group Company,Shenmu 719315,China)

机构地区：[1]西安交通大学金属材料强度国家重点实验室,西安710049 [2]神华神东煤炭集团公司设备维修中心,神木719315

出　　处：《中国腐蚀与防护学报》2020年第6期585-591,共7页Journal of Chinese Society For Corrosion and Protection

基　　金：西安市科技创新计划(201805064ZD15CG48).

摘　　要：针对所提出的恒电位脉冲电沉积铜锡技术,研究工艺条件对镀层成分、晶粒尺寸及耐蚀性能的影响规律,摸索恒电位脉冲电沉积高锡青铜的最优工艺。利用SEM观察分析恒电位脉冲与恒电流脉冲电沉积铜锡镀层的形貌及晶粒尺寸,结合EDS分析电沉积方式对镀层成分分布的影响规律,使用电化学工作站表征镀层的耐蚀性。结果表明,使用占空比33%、沉积电位3 V的恒电位脉冲电沉积工艺,降低了镀层溶解几率而维持络合离子迁移、沉积驱动力,因而对不同尺寸零件均可稳定获得高锡青铜镀层。相同初始条件下,恒电流脉冲镀层平均厚度约6μm;而恒电位脉冲具有更大的沉积速率,膜层厚度在10μm以上,且镀层成分比恒电流脉冲镀层更均匀、孔隙率低、晶粒团簇少、耐蚀性能优良,在截面积为78.5 mm^2的试样上镀层阻抗较恒电流脉冲提高了两倍。恒电位脉冲还可获得纳米Cu-Sn镀层,晶粒尺寸小于100 nm。相对恒电流脉冲,恒电位脉冲电沉积提高了铜锡镀层质量及耐蚀性,且有利于复杂零件的成分控制及自动化生产。Aiming at the proposed potentiostatic pulse electrodeposition of Cu-Sn alloy,the influence of process parameters on the composition,grain size and corrosion resistance of prepared coatings is studied.The morphology,grain size,chemical composition and corrosion behavior of the Cu-Sn coatings electrodeposited by potentiostatic pulse technology or constant-current pulse technology are characterized by means of scanning electron microscope(SEM)with energy dispersive spectroscopy(EDS)and electrochemical workstation.It is found that potentiostatic pulse process of Cu-Sn electroplating with the duty ratio of 33%and potential of 3 V could reduce the dissolution probability of the plating layer and maintained the complex ion migration and deposition driving force,so that the high-tin bronze coating can be obtained on parts of different size.The grain size of the coating on the part with surface area 78.5 mm^2 is less than 100 nm.Under the same initial conditions,the electrodeposition rate of the potentiostatic pulse technology is faster than that of the constant current pulse technology,besides the plated alloy presents much better composition uniformity and the formed coating possesses only few of pores and crystallite clusters,therefore the coating exhibits corrosion resistance 2 times higher than that made by constant-current pulse.Compared with the constant current pulse technology,the potentiostatic pulse electrodeposition is beneficial to improve the quality and corrosion resistance of copper-tin plating and which may facilitate the introduction of processing automation or composition control for complex parts as well.

关 键 词：高锡青铜 恒电位脉冲 恒电流脉冲 电沉积 耐蚀性 

分 类 号：TQ153.2[化学工程—电化学工业]