Conference paper

Corrosion Characteristics of Raw and Anodised Aluminium

S. Islamović ; University of Sarajevo, Faculty of Science, Department of Chemistry, Bosnia and Herzegovina
F. Korać ; University of Sarajevo, Faculty of Science, Department of Chemistry, Bosnia and Herzegovina
J. Ostojić ; University of Sarajevo, Faculty of Science, Department of Chemistry, Bosnia and Herzegovina
M. Kezo ; University of Sarajevo, Faculty of Science, Department of Chemistry, Bosnia and Herzegovina
S. Gutić ; University of Sarajevo, Faculty of Science, Department of Chemistry, Bosnia and Herzegovina
L. Koštroman ; University of Sarajevo, Faculty of Science, Department of Chemistry, Bosnia and Herzegovina
A. Halilović ; University of Sarajevo, Faculty of Science, Department of Chemistry, Bosnia and Herzegovina

Abstract

Corrosion resistance of aluminium and its alloys in different media can be improved by many procedures. One of the most used methods is anodisation or anodic oxidation, which is commonly known as anodising. Solutions of: NaCl, w = 3 %, HCl, w = 3 %, H₂ SO₄ , w = 10 %, NaCl + NaOH (pH = 10.09), NaOH (pH = 10.17), and seawater taken from Ploče were used as corrosive media. Anodisation enables higher potentials in all corrosive environments, indicating that a protective oxide film has been formed. This oxide layer is the most stable in a solution of sulphuric acid, and has the lowest protective role in 3 % HCl solution, 3 % NaCl solution and seawater. By increasing the thickness of anodising from 10 to 20 micrometres, no improvement of the corrosion protection was achieved, except in the NaOH solution. Anodising also reduces the polarization resistance by a similar dependence of the corrosive environment. An even greater and similar protective effect is exhibited by anodised aluminium with a thickness of 20 micrometres. Anodising decreases the corrosion rate by several orders of magnitude, which confirms that aluminium anodising protects against corrosion. Values are from 3.57 to 2699.00 mm a-1

Keywords

Aluminium; Corrosion

Hrčak ID:

105194

URI

https://hrcak.srce.hr/105194

Publication date:

8.7.2013.

Article data in other languages: croatian

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