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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Correlating the Modes of Corrosion with Microstructure in the Friction Stir Welded AA2198-T8 Alloy in Aqueous Hydrogen Peroxide-Chloride Medium

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Author(s):
Carvalho Machado, Caruline de Souza [1] ; Donatus, Uyime [1] ; Milagre, Mariana X. [1] ; Mogili, Naga V. V. [2] ; Giorjao, Rafael A. R. [2] ; Klumpp, Rafael Emil [1] ; Araujo, Joao Victor de S. [1] ; Ferreira, Raphael Oliveira [3] ; Costa, Isolda [1]
Total Authors: 9
Affiliation:
[1] CNEN, IPEN, Av Prof Lineu Prestes 2242, BR-05508000 Sao Paulo - Brazil
[2] CNPEM, Brazilian Nanotechnol Natl Lab LNNano, R Giuseppe Maximo Scolfaro 10000, BR-13083970 Campinas, SP - Brazil
[3] Univ Sao Paulo, Dept Engn Mecatron & Sistemas Mecan Poli, Lab Fenomenos Superficie, Av Prof Luciano Gualberto 380, BR-05508010 Sao Paulo - Brazil
Total Affiliations: 3
Document type: Journal article
Source: CORROSION; v. 75, n. 6, p. 628-640, JUN 2019.
Web of Science Citations: 2
Abstract

In this study, different types of localized corrosion in the friction stir welding (FSW) zones of an AA2198-T8 when the alloy is subjected to a corrosion test in a hydrogen peroxide-chloride solution (according to ASTM G110 standard) has been investigated. The corrosion modes were correlated with microstructure, especially with respect to the T1 phase and coarse Al-Cu-Fe phase distribution across the weldment. Simulated thermal profile and microhardness measurements were used to establish the variations in T1 phase distribution. Two types of corrosion were observed in the FSW zones: intense pitting and intergranular corrosion-type I; and the formation of cavities and trenches-type II. Type I is associated with the T1 phase while type II is associated with Al-Cu-Fe coarse intermetallics. Both types were found on the base metal (BM) and heat affected zone, but the type I reduced in the latter toward the stir zone (SZ). The SZ/thermo-mechanically affected zone (TMAZ) exhibited only type II. Also, Cu enrichment was observed around the type II sites in the SZ/ TMAZ. Furthermore, an inverse correlation between microhardness and corrosion resistance which was related to T1 phase concentration in the different zones was also observed. Moreover, the SZ and BM were isolated and evaluated by an immersion test and electrochemical analysis using the ASTM G110 test solution. The results indicated galvanic coupling effects, as the SZ was strongly attacked when exposed separately compared to when it was coupled with the other zones. (AU)

FAPESP's process: 13/13235-6 - Investigation on the localized corrosion and the fatigue corrosion resistance of high strength aluminum alloys joined by friction stir welding (FSW)
Grantee:Isolda Costa
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 17/03095-3 - Investigation on corrosion susceptibility of Al-Cu-Li alloys by friction stir welding (FSW) through scanning vibrating electrode technique (SVET)
Grantee:Uyime Donatus
Support Opportunities: Scholarships in Brazil - Post-Doctoral