Quasi-in situ immersion characterization of grain structures evolution revealing the corrosion resistance of Al-Zn-Mg alloys with various Sc additions

• Published in: Journal of Central South University Vol. 30; no. 12; pp. 3964 - 3974
• Main Authors: Li, Ming-gao, Sun, Mei-yu, Meng, Ling-han, Guo, Xiao-bin
• Format: Journal Article
• Language: English
• Published: Changsha Central South University 01.12.2023; Springer Nature B.V
• Subjects: Aluminum base alloys; Corrosion effects; Corrosion resistance; Corrosion tests; Engineering; Exfoliation corrosion; Grain boundaries; Heat treatment; Magnesium; Mechanical properties; Metallic Materials; Precipitates; Recrystallization; Scandium; Submerging; Surface layers; Texture; Zinc; Al-Zn-Mg合金; Al-Zn-Mg alloy; textures; 耐蚀性; 微观结构; 织构分析; microstructures; 剥落腐蚀; corrosion resistance; exfoliation corrosion
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-023-5491-5

Al-Zn-Mg alloys have been investigated for the effect of Sc additions on corrosion resistance. The addition of Sc to Al-Zn-Mg alloys can more effectively retard recrystallisation during heat treatment and improve mechanical properties. Sc-added alloys show significant discontinuity in grain boundary precipitation. In addition, the distribution spacing of η precipitates at the grain boundary is the largest in the alloy with Sc content of 0.29 wt.%. The exfoliation corrosion test and microstructural recrystallisation analysis show the inhibitory effect of Sc addition on recrystallisation and hence the improvement in corrosion resistance. In-situ immersion corrosion results indicated that the uncorroded texture in Al-Zn-Mg alloy with 0.29 wt.% Sc content first showed a rapid decrease and then a rapid increase. The addition of Sc to Al-Zn-Mg alloy plays an important role in improving the surface texture and increasing the corrosion resistance in the early stages of corrosion.