Oxide film formation on a microcrystalline Al alloy at various temperatures in neutral borate solution

Journal Article · Wed Oct 01 04:00:00 EDT 1997 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1838022· OSTI ID:562201

Thomas, S C; Birss, V I ^[1]

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1. Univ. of Calgary, Alberta (Canada). Dept. of Chemistry

FVS0812 is a rapidly solidified Al alloy consisting of an intermetallic (dispersoid) phase, containing Al, Fe, V, and Si, surrounded by a predominantly Al matrix. The electrochemical behavior and the oxide film structure of FVS0812 were compared to that of its two phases, as well as pure Al, in neutral borate solution at a range of temperatures. While in acidic solution, FVS0812 is unable to form an adherent, thick, porous oxide film, in 60 C neutral solution, stable, although substantially thinner, porous oxides are formed on Al, FVS0812, and the matrix. In contrast to its dissolution in acidic medium, the dispersoid phase is retained within the porous film formed on the alloy in neutral solution. However, the dispersoid phase also causes the formation of a somewhat contorted porous oxide structure. Impedance measurements suggest that solution penetration into fine flaws in the barrier oxide at the barrier/porous oxide interface, a phenomenon exacerbated by increased temperature and time at applied potentials, is more prevalent for FVS0812 than for Al and the matrix.

• Sponsoring Organization: USDOE
• OSTI ID: 562201
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 10 Vol. 144; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
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BORATES
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PROTECTIVE COATINGS
SOLIDIFICATION