Pitting Corrosion Resistance of Anodized Aluminum Alloy Processed by Severe Plastic Deformation

• Son In-Joon

  Department of Materials Process Engineering, Kyushu University

• Nakano Hiroaki

  Department of Materials Science & Engineering, Kyushu University

• Oue Satoshi

  Department of Materials Science & Engineering, Kyushu University

• Kobayashi Shigeo

  Department of Applied Chemistry and Biochemistry, Kyushu Sangyo University

• Fukushima Hisaaki

  Department of Materials Science & Engineering, Kyushu University

• Horita Zenji

  Department of Materials Science & Engineering, Kyushu University

Abstract

The effect of equal-channel angular pressing (ECAP) on the pitting corrosion resistance of anodized Al and Al-Mg alloy was investigated by electrochemical techniques in a solution containing 0.2 mol/L of AlCl₃ and by surface analysis. The time required for initiating pitting corrosion of anodized Al was longer with ECAP than without, indicating improvement in the pitting corrosion resistance by application of ECAP. However, in anodized Al-Mg alloy, the pitting corrosion occurred earlier with ECAP than without, showing that the corrosion resistance was worse with ECAP than without. SEM and EPMA observation revealed that pitting corrosion of anodized Al occurred around the impurity precipitates and that the size of the impurity precipitates decreased as a result of the ECAP. The improvement in pitting corrosion resistance of anodized Al by ECAP appears to be attributable to a decrease in the size of impurity precipitates. On the other hand, in anodized Al-Mg alloy, cracks occurred in the anodic oxide films during initial corrosion and the cracks were larger with ECAP than without. It is assumed that the pitting corrosion was promoted by the cracks due to the higher internal stress resulting from ECAP.

Journal

• MATERIALS TRANSACTIONS

  MATERIALS TRANSACTIONS 48 (1), 21-28, 2007

  The Japan Institute of Metals and Materials

Keywords

• aluminum
• aluminum-magnesium alloy
• equal-channel angular pressing
• anodizing
• pitting corrosion

Details

• CRID: 1390001204249448192
• NII Article ID: 130004453332
• NII Article ID: 10018665975
• NII Book ID: AA1151294X
• DOI: 10.2320/matertrans.48.21
• COI: 1:CAS:528:DC%2BD2sXit1Whs7k%3D
• ISSN: 13475320
• ISSN: 13459678
• NDL BIB ID: 8597186
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I8597186
• Web Site: https://www.jstage.jst.go.jp/article/matertrans/48/1/48_1_21/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed