Influence of γ-Alumina on the Growth of Barrier Anodic Films on Aluminum

DOI Web Site Web Site 1 References Open Access
  • Kobayashi Kenzo
    Department of Chemistry, Faculty of Science and Technology, Keio University
  • Shimizu Ken-ichi
    Department of Chemistry, Faculty of Science and Technology, Keio University
  • Teranishi Daisuke
    Department of Chemistry, Faculty of Science and Technology, Keio University

Bibliographic Information

Other Title
  • バリヤー型Alアノード酸化皮膜の成長に及ぼすγ-Al<sub>2</sub>O<sub>3</sub>結晶の影響
  • バリヤー型Alアノード酸化皮膜の成長に及ぼすγ-Al2O3結晶の影響
  • バリヤーガタ Al アノード サンカ ヒマク ノ セイチョウ ニ オヨボス ガ
  • Influence of &gamma;-Alumina on the Growth of Barrier Anodic Films on Aluminum

Search this article

Description

Electropolished 99.99% aluminum sheets were heat-treated in air at 550°C for 15min to form a thin layer of thermal oxide containing γ-alumina crystals of sizes up to about 0.2μm. The thermally oxidized specimens were then anodized in 0.1M ammonium pentaborate solution at 20°C with a constant current density of 50A/m2. Transmission electron microscopy and electron diffraction analysis of the stripped anodic films have shown that the films consist of amorphous, γ′ and γ-alumina. γ′-alumina occurs as band-like regions of relatively uniform widths surrounding γ-alumina crystals originally present in the thermal oxide. The width of the band of γ′-alumina was about 10 and 50nm for the films formed to 50 and 100V, respectively, indicating a relatively rapid development of γ′-alumina regions with increasing forming voltage. The development of the band of γ′-alumina was also found to be strongly inhibited when the thermally oxidized specimens were anodized in such solutions as aqueous ammonium dihydrogen phosphate, ammonium tartrate and ammonium citrate.

Journal

  • CORROSION ENGINEERING

    CORROSION ENGINEERING 35 (7), 393-398, 1986

    Japan Society of Corrosion Engineering

References(1)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top