An in situ measure method to study deposition mechanism of electroless Ni-P plating on AZ31 magnesium alloy  

原位测量法研究AZ31镁合金表面化学镀Ni-P的沉积机理(英文)

作　　者：秦铁男[1] 马立群[1] 姚妍[1] 倪聪[1] 赵相玉[1] 丁毅[1] 

机构地区：[1]南京工业大学材料科学与工程学院,南京210009

出　　处：《Transactions of Nonferrous Metals Society of China》2011年第12期2790-2797,共8页中国有色金属学报（英文版）

基　　金：Project supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), China

摘　　要：An in situ method was designed to measure a continuous open circuit potential （OCP） curve of AZ31 magnesium alloy and to observe the morphology variation of Ni-P coating during the process of the electroless plating. The deposition mechanism of the electroless Ni-P plating on AZ31 Mg alloy was studied by OCP curve, scanning electron microscopy （SEM）, and energy dispersion spectroscopy （EDS）. The process of electroless Ni-P plating contains the coating formation stage and the coating growth stage. The formation stage includes three procedures, i.e., the nucleation and growth of Ni crystallites, the extension of the coating in two-dimensional （2D） direction and the coalescence of the coating along three-dimensional （3D） direction. SEM investigations demonstrate that the spherical nodules of the Ni-P coating are not only formed during the coating growth stage, but also generated in the initial deposition stage of electroless Ni-P plating. The variation of the coating rates at different deposition stages corresponds to the deposition mechanism of their respective deposition stage.设计一种原位方法去测量AZ31镁合金在化学镀Ni-P过程中基体在镀液中的开路电位和体积表面的镀层形貌变化。通过开路电位曲线、扫描电子显微镜和能谱分析研究AZ31镁合金化学镀Ni-P的沉积机理。结果表明:化学镀Ni-P的沉积过程包括镀层的形成过程和镀层的增厚过程,其中镀层的形成过程又包括镍晶核的形核和长大过程、镀层的二维扩展过程和镀层的三维搭接过程。扫描电镜分析证实了Ni-P镀层的球形瘤状物不仅形成于镀层的增厚阶段,同样也形成于Ni-P镀层的初始沉积阶段。不同沉积阶段的沉积速度变化分别与各自的沉积机理对应。

关 键 词：magnesium alloy electroless Ni-P deposition NUCLEATION coating rate 

分 类 号：TG174.4[金属学及工艺—金属表面处理]