Abstract
In this work, the behaviour of arc-sprayed aluminium (1050) coatings was investigated under full artificial seawater immersion and compared with simulated splash zone conditions under droplets of artificial seawater exposed to controlled conditions. To gain a better insight into the mechanism of corrosion of thermally sprayed coatings, tests were also performed on 1050 aluminium sheet. The effectiveness of TSA coatings was evaluated using electrochemical techniques and corrosion products were examined by SEM/EDX and Raman spectroscopy. Sulphur containing corrosion products, such as felsobanyaite, were found on the coating as well as on the Al sheet. This highlights the importance of using seawater, and not NaCl solutions, as a corrosive medium simulating marine environment. Moreover, it was observed that cathodic and anodic regions on thermally sprayed coatings were not easily distinguishable, whereas on Al sheet, cathodic areas were located in the spreading region, where carbonate corrosion product (dawsonite) was detected. Full immersion studies revealed the need for pre-exposing samples before electrochemical testing, in order to predict the long-term behaviour of the coating in marine service.
Original language | English |
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Pages (from-to) | 124-133 |
Number of pages | 10 |
Journal | Surface and Coatings Technology |
Volume | 374 |
DOIs | |
Publication status | Published - 25 Sept 2019 |
Bibliographical note
Funding Information:The authors wish to acknowledge TWI Ltd. and EPSRC (EPSRC CDT Grant No: EP/L016206/1 ) in Innovative Metal Processing for financial support.
Funding Information:
This publication was made possible by the sponsorship and support of Lloyd's Register Foundation, a charitable foundation helping to protect life and property by supporting engineering-related education, public engagement and the application of research. The work was enabled through, and undertaken at, the National Structural Integrity Research Centre (NSIRC), a post-graduate engineering facility for industry-led research into structural integrity established and managed by TWI through a network of both national and international Universities.
Publisher Copyright:
© 2019 Elsevier B.V.
Keywords
- Aluminium corrosion products
- Cathodic protection
- Marine corrosion
- Metallic coatings
- Thermal spray coatings
- Thermally sprayed aluminium
ASJC Scopus subject areas
- General Chemistry
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry