Formation mechanism of electroless plating nickel-based composite coating on highly active rare earth magnesium alloys and its corrosion resistance and adhesion performance  

高活性稀土镁合金化学镀镍基复合涂层的形成机理及其性能

作　　者：WANG Bo LI Jia-wei XIE Zhi-hui LIU Kang XU Tao YU Gang 王波;李佳蔚;谢治辉;刘康;徐涛;余刚(College of Chemistry and Chemical Engineering,Hunan University,Changsha 410012,China;Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province,China West Normal University,Nanchong 637002,China;Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]College of Chemistry and Chemical Engineering,Hunan University,Changsha 410012,China [2]Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province,China West Normal University,Nanchong 637002,China [3]Central South University of Forestry and Technology,Changsha 410004,China

出　　处：《Journal of Central South University》2024年第10期3517-3531,共15页中南大学学报（英文版）

基　　金：Project(5227010679)supported by the National Natural Science Foundation of China。

摘　　要：The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on active anodic oxide film and the structure and properties of the composite coating were studied by several surface and electrochemical techniques.The results showed that Ag nanograins with an average size of 10 nm were embedded into the anodic oxide film with pores of 0.1−2μm.Ag nanoparticles provided a catalytic site for the deposition of Ni-B alloy,and the Ni crystal nucleus was first grown in horizontal mode and then in cylindrical mode.The corrosion potential of the composite coating increased by 1.37 V and the corrosion current reduced two orders of magnitude due to the subsequent deposition of Ni-P alloy.The high corrosion resistance was attributed to the misaligning of these micro defects in the three different layers and the amorphous structure of the Ni-P alloy in the outer layer.These findings provide a new idea for electroless nickel plating on anodic oxide film.本文在高活性稀土镁合金上开发了含活性位点的阳极氧化膜和其上化学镀镍工艺。采用表面和电化学技术研究了活性阳极氧化膜上化学镀镍形成机理及复合涂层的结构与性能。结果表明,在孔径为0.1~2μm的阳极氧化膜中嵌入了平均尺寸为10 nm的Ag单质纳米颗粒。Ag纳米粒子为Ni-B合金的沉积提供了催化位点,使Ni晶核首先以水平模式生长,后以圆柱模式生长。由于随后沉积了高磷含量的Ni-P合金,三种不同涂层中的微缺陷形成错位以及外层中Ni-P合金的非晶态结构造就了复合镀层的高耐蚀性,复合涂层的腐蚀电位增加了1.37 V,腐蚀电流降低了两个数量级。这些发现为在阳极氧化膜上进行化学镀镍提供了新思路。

关 键 词：rare earth magnesium alloy electroless nickel plating composite coating Ag+activation active anodic oxidation film growth mechanism 

分 类 号：TG174.4[金属学及工艺—金属表面处理]