Mechanism of Early Stage Corrosion for Boric-sulfuric Acid Anodized 2A97 Al-Cu-Li Alloy Under Tropical Marine Atmosphere

Journal of Materials Engineering. 2016;44(9):8-15 DOI 10.11868/j.issn.1001-4381.2016.09.002

 

Journal Homepage

Journal Title: Journal of Materials Engineering

ISSN: 1001-4381 (Print)

Publisher: Journal of Materials Engineering

LCC Subject Category: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials

Country of publisher: China

Language of fulltext: Chinese

Full-text formats available: PDF, HTML

 

AUTHORS

LUO Chen (Aviation Key Laboratory of Science and Technology on Advanced Corrosion and Protection for Aviation Materials, Beijing Institute of Aeronautical Materials, Beijing 100095, China)
Sergiu P. Albu (School of Materials, The University of Manchester, Manchester M13 9PL, UK)
SUN Zhi-hua (Aviation Key Laboratory of Science and Technology on Advanced Corrosion and Protection for Aviation Materials, Beijing Institute of Aeronautical Materials, Beijing 100095, China)
TANG Zhi-hui (Aviation Key Laboratory of Science and Technology on Advanced Corrosion and Protection for Aviation Materials, Beijing Institute of Aeronautical Materials, Beijing 100095, China)
LU Feng (Aviation Key Laboratory of Science and Technology on Advanced Corrosion and Protection for Aviation Materials, Beijing Institute of Aeronautical Materials, Beijing 100095, China)
Xiaorong Zhou (School of Materials, The University of Manchester, Manchester M13 9PL, UK)

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Time From Submission to Publication: 44 weeks

 

Abstract | Full Text

Optical microscopy(OM), scanning electron microscopy(SEM), EDX and EIS combined with ultramicrotomy were employed to investigate the micro morphology, chemical composition and electrochemical properties of anodized 2A97 Al-Cu-Li alloy before and after atmospheric corrosion. The results show that when electrolytes containing combinations of tartaric-sulfuric or boric-sulfuric acid are used to grow the films at different temperatures, boric acid addition and higher temperature allow for higher current density that speeds up the film growth. The pore geometry and structure is similar for different electrolytes. Dispersive dark rusty spots composed of O, Al, Cl, Cu are present on the boric-sulfuric acid anodized specimen after exposure in tropical marine atmosphere for 1 month. Deposition of white corrosion product is found on the specimen surface as well. Severe pitting occurs and develops deeply into the alloy substrate after elongated outdoor exposure. Corrosion propagation is associated with <i>θ</i>-phase particles.