Gradient textures induce micro-galvanic corrosion on Mg

• Published in: Journal of alloys and compounds Vol. 1005; p. 176119
• Main Authors: Bai, Jing, Sun, Chao, Wang, Cheng, Shao, Yi, Meng, Jiao, Dong, Qiangsheng, Xue, Feng, Chu, Chenglin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2024
• Subjects: Magnesium; Micro-galvanic corrosion; Quasi-in-situ EBSD; Texture; Quasi-in-situ EBSD; Magnesium; Texture; Micro-galvanic corrosion
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2024.176119

In this study, the reason for the non-basal-plane-rich area more corrosion resistant than the basal-plane area on pure Mg in NaCl electrolyte was demonstrated based on quasi-in-situ EBSD observations. Due to the higher concentration of dissimilar crystallography orientations in the basal-plane-rich area, the gradient textures and ‘micro-texture’ galvanic couples were promoted. This exacerbates the progression of localized corrosion in basal-plane-rich area, ultimately deteriorating the overall corrosion performance of Mg. Randomizing the gradient texture diminishes the tendency towards micro-galvanic corrosion and enhances the corrosion resistance of Mg. These findings shed light on yet another facet of complex mechanism of Mg corrosion. •Quasi-in-situ EBSD observations were used to investigate the influence of texture on Mg corrosion.•The reason for higher corrosion resistance of non-basal-plane-rich area than basal-plane-rich area in Mg was identified.•A ‘micro-texture’ galvanic corrosion mechanism induced by gradient textures was proposed and rationalized.•The model elucidating localized corrosion mechanism affected by texture were established.