In-situ observation on filiform corrosion propagation and its dependence on Zr distribution in Mg alloy WE43  

作　　者：Zhi Chen Huizhong Li Xiaopeng Liang Ming-Chun Zhao Kelong Zhang Andrej Atrens 

机构地区：[1]School of Materials Science and Engineering,Central South University,Lushan Road,Changsha 410083,China [2]State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China [3]School of Mechanical Mining Engineering,University of Queensland,Brisbane,Qld 4072,Australia

出　　处：《Journal of Magnesium and Alloys》2023年第11期4282-4300,共19页镁合金学报（英文）

基　　金：Financially supported by Chinese Natural Science Foundation (NSFC,China) (No.51874368)。

摘　　要：The direct industrial importance of the corrosion resistance in WE43 is best emphasized by its extensive use in the automotive, aerospace and electronic industries where weight reduction is a necessary requirement. In this work, the corrosion especially the filiform corrosion in a 3.5 wt.% Na Cl solution and their dependence on the Zr distribution for WE43 were studied by weight loss tests, hydrogen evolution tests, electrochemical measurements and microscopic analyses. The Zr distribution significantly influenced the initiation and propagation of the filiform corrosion, and accordingly significantly influenced the corrosion rate. WE43 with a cluster Zr distribution displayed filiform corrosion throughout the entire surface with an irregular network distribution of filaments. WE43 with a uniform line Zr distribution exhibited only a few examples of linear filiform corrosion. WE43 with a dispersive Zr distribution exhibited no filiform corrosion. The stability of the corrosion film was responsible for the filiform corrosion. Anodic polarisation promoted the initiation and progression of the filiform corrosion,while cathodic polarisation had an inhibiting effect on the filiform corrosion. The serrated interface of the filiform corrosion increased the contact area between the substrate and the corrosive medium, and hence increased the corrosion rate.

关 键 词：WE43 Mg alloy Filiform corrosion Zr distribution Corrosion rate 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG172[金属学及工艺—金属材料]