A closer inspection of a grain boundary immune to intergranular corrosion in a sensitised Al-Mg alloy. (1st April 2018)

• Record Type: Journal Article
• Authors: Zhang, Ruifeng; Qiu, Yao; Qi, Yuanshen; Birbilis, Nick
• Is Part Of: Corrosion science. Volume 133(2018)
• Page Start: 1
• Page End: 5
• Publication Date: 2018-04-01
• Subjects: A. Aluminium -- A. Alloy -- B. SEM -- B. TEM -- C. Intergranular corrosion; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2018.01.009
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Grain boundaries containing β-phase precipitates and immune to IGC are presented. The role of β-phase precipitate continuity in sensitisation is elaborated. The influence of grain boundary misorientation angle on IGC is demonstrated. Abstract: The intergranular corrosion of Al-Mg alloys arises from sensitisation due to thermal exposure. Here, a protected low angle (8.7°) grain boundary which hinders the intergranular corrosion propagation in a sensitised (150°/7 d) Al-Mg alloy was studied in detail. Discrete β-phase was observed on this protected boundary, but with a lower continuity compared to the other fully (or partially) dissolved grain boundaries. The results herein seek to unify the relationship between β-phase continuity and grain boundary misorientation angle as critical for intergranular corrosion propagation in the studied alloy.