Pitting corrosion of aluminum-alloys at aluminum(3) iron inclusions: The effect of local chemical environment and transport phenomena

Al$\sb3$Fe and α-AlFeSi type intermetallic particles depassivate the passive film of many commercial aluminum alloys through a local alkalization mechanism in an aerated NaCl solution. This mechanism was verified on the basis of polarization data, theoretical modeling, and in-situ optical observations for commercial aluminum alloys 6061-T6, 5454-H32, and Al-8%Fe. The local alkalization results in either ditching or pitting at the interfacial region between the particles and the aluminum matrix. A micro-disk electrode concept was adopted to calculate the oxygen reduction limiting current at intermetallics to explain the mechanism and predict the related electrochemical behavior. It is suggested that dissolved oxygen acts as a depassivator for the pitting on commercial aluminum alloys in an aerated NaCl solution.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Paik, Chi-Hum

Contributors dc:contributor

• Alkire, Richard C.

• Chemical Engineering

Statement dc:rights

• Copyright 1993 Paik, Chi-Hum

Language dc:language

eng

Identifier

AAI9329127
(UMI)AAI9329127

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/19040