Corrosion behavior of Mg-5.7Gd-1.9Ag Mg alloy sheet

This paper focuses on the corrosion behavior of Mg-5.7Gd-1.9Ag alloy sheets with high strength-ductility synergy in the 3.5 wt% NaCl solution prepared by a combined route of rolling and aging. Electrochemical measurements indicate that the rolled sheet exhibits a significantly improved corrosion resistance as compared to its as-cast counterpart. Subsequent aging, as a widely used strengthening method, decreases corrosion resistance to a certain extent. However, the aged sheet still has enhanced corrosion resistance as compared to its as-cast counterpart. The observed corrosion migration in the present Mg-5.7Gd-1.9Ag Mg alloy mainly stems from the evolution of second phases, but not the grain size and texture. A small number of the micron beta phase particles is incapable of promoting severe galvanic corrosion and thus endows the rolled sheet with good corrosion resistance, while the massive submicron beta phase particles along grain boundaries and dense gamma '' nanoplates within grains in the aged sheet bring out severe galvanic corrosion and thus accelerate corrosion. (c) 2022 Elsevier B.V. All rights reserved.