Effect of hierarchical precipitates on corrosion behavior of fine-grain magnesium-gadolinium-silver alloy. (January 2022)

• Record Type: Journal Article
• Authors: Xu, Bingqian; Sun, Jiapeng; Han, Jing; Yang, Zhenquan; Zhou, Hao; Xiao, Lirong; Xu, Songsong; Han, Ying; Ma, Aibin; Wu, Guosong
• Is Part Of: Corrosion science. Volume 194(2022)
• Publication Date: 2022-01
• Subjects: A. Magnesium -- B. EIS -- B. Polarization -- B. STEM -- C. Interfaces; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2021.109924
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: An equal channel angular pressing (ECAP) process is used to obtain a fine-grain magnesium-gadolinium-silver alloy, and hierarchical precipitates embedded in the fine-grain matrix are achieved by subsequent peak-aging. These hierarchical precipitates are composed of the β phase sub-microparticles, β phase nanoparticles, γ" phase nanoplates, and β' phase nanoplates. They facilitate corrosion in the 3.5 wt% NaCl solution to some extent due to micro-galvanic corrosion. However, compared to those precipitates in the as-cast alloy, the spatial redistribution of the hierarchical precipitates improves the corrosion resistance of the material, which is possibly attributed to the formation of a protective corrosion product film. Highlights: Peak-aging following equal channel angular pressing is conducted on Mg-Gd-Ag alloy. Hierarchical precipitates are successfully achieved in fine-grain Mg-Gd-Ag alloy. Its corrosion rate may be controlled by hierarchical precipitates.