【作者】 杨海燕； 郭兴伍； 吴国华； 丁文江；

【Author】 Haiyan Yang~(1,2),Xingwu Guo~(1,2),Guohua Wu~(1,2),Wenjiang,Ding~(1,2) (1.National Engineering Research Center of Light Alloy Net Forming,Shanghai Jiaotong University,Shanghai,200240,PR China 2.State key laboratory of metal matrix composites,Shanghai Jiaotong University,Shanghai,200240,PR China)

【机构】 上海交通大学轻合金精密成型国家工程研究中心； 上海交通大学金属基复合材料国家重点实验室；

【摘要】 镁合金由于化学活性高,在水溶液中电镀时存在很多困难。本文采用氯化胆碱-尿素离子液体作为溶剂,对Zn的电沉积行为和AZ91D镁合金上电镀Zn进行了研究,并对Zn镀层的耐腐蚀性能进行了电化学测试。结果表明,AZ91D镁合金在氯化胆碱-尿素中电镀可获得Zn镀层,浸Zn前处理能使Zn的沉积电位发生正移,无需形核过电位,且能提高镀层结合力;脉冲电镀比恒流电镀更利于获得致密均匀、与基体结合良好的Zn层;恒流电镀Zn层后,基体AZ91D镁合金的开路电位OCP从-1610mV正移至-1265mV,腐蚀电流i_corr从14.9μA·cm^-2降为10.2μA·cm^-2,脉冲电镀Zn层后开路电位OCP进一步正移至-1140mV,腐蚀电流i_corr降为6.5μA·cm^-2,与纯Zn=6.6μA·cm^-2相当。更多还原

【Abstract】 In aqueous electrolytes,electrodeposition on Mg alloys is still a challenge because Mg has high chemical and electrochemical activities.In present study,electrodeposition behavior of Zn and electrodeposition of Zn on AZ91D in ChCl-urea ionic liquids was investigated and the corrosion resisitance of the Zn layers were studied by electrochemical testing.The results show,Zn layers can be deposited on AZ91D by electrodeposition in ChCl-urea ionic liquids.By Zn immersion on AZ91D,the reduction potetial of Zn moves in positive direction without nucleation overpotential and the adhesion of Zn layers is improved.Application of pulse deposition was superior to galvanostatic deposition in producing dense,uniform and cohesive Zn layers.By galvanostatic deposion Zn layers,the OCP of AZ91D moves in positive direction from-1610mV to-1265mV and the corrosion current density icorr decreases from 14.9μ·cm^-2 to 10.2μA·cm^-2.By pulse deposion Zn layers the,OCP moves in positive direction further to-1140mV and the corrosion current density icorr decreases to 6.5μA·cm^-2,comparable to pure Zn=6.6μA·cm^-2.更多还原