Porous/barrier composite films formed on aluminum by re-anodizing

Sachiko Ono, Tetsuya Osaka, Noboru Masuko

Research output: Contribution to journalArticle

Abstract

The structure and the formation behavior of porous/barrier composite oxide films formed on aluminum by re-anodizing in a boric acid/ammonium borate solution have been studied by transmission electron microscopy combined with ultramicrotomy. The porous film was formed in an oxalic acid solution. The porous/barrier composite film is amorphous, whereas a crystalline film grows when the porous film is hydrated before the re-anodizing to form hydrous alumina platelets in the pores. The size and the volume of both crystals and voids increase with anodizing time. The thickness of the various types of barrier films formed at a given current density up to 350 V in the borate solution decreases in the order: the amorphous region of the barrier film > the barrier/porous amorphous composite film > the hydrated porous/barrier crystalline composite film > the crystalline region of the barrier film.

Original languageEnglish
Pages (from-to)1005-1011
Number of pages7
JournalElectrochemistry
Volume64
Issue number9
Publication statusPublished - 1996

    Fingerprint

Keywords

  • Barrier Film Thickness
  • Composite Film
  • Re-anodizing of Aluminum
  • Ultramicrotomy

ASJC Scopus subject areas

  • Electrochemistry

Cite this