作　　者： ; ; ; ; ;

机构地区： 中国科学院金属研究所金属腐蚀与防护国家重点实验室

出　　处： 《腐蚀科学与防护技术》 2010年第4期307-311,共5页

摘　　要： 采用SEM、EDXS、XPS及电化学测试方法对镁合金表面镀锌电沉积过程中的界面反应及镀层生长规律进行研究.结果表明,采用前处理方法后,镁合金表面膜的成分由Mg(OH)2/Mg(OH)HCO3转变为MgF2+Zn,有效地抑制了镁在电镀液中的腐蚀,促进了锌在电极表面的形核与生长,获得的锌镀层与基体结合力优良.采用计时电流法对锌镀层电结晶的研究发现:低过电位下电极表面经历了两次形核过程,镀层沉积物颗粒显得致密,而高过电位下电极表面只经历了一次形核过程,镀层沉积物颗粒变得松散. Formation of intermidiate layer between Mg alloy and Zn coating and on which the growth mechanism of zinc coating were investigated by SEM,EDXS,XPS and electrochemical analysis.It was indicated that the chemical composition of surface film on Mg alloy was changed from Mg（OH）2/Mg（OH）HCO3 to MgF2＋Zn after pre-treatment,which could effectively restrain anodic dissolving of Mg in electrolyte and promote cathode reduction and nucleation process of Zn on the electrode,and therefore benefited to the deposition of adhesive Zn coating.The study of elecro-crystallization process of Zn deposition revealed that under low-overpotentials Zn nucleation process was a two step process resulting in a compact deposition,on the contrary,under high-overpotentials it was a one step process resulting in a coarse deposition.

关 键 词： 镁合金 电镀锌 计时电流法 形核

领　　域： [金属学及工艺] [金属学及工艺]