A microellipsometric study of the passive film formation on Al-Ta alloys; 1: Solid solution alloys

Journal Article · Sun May 01 00:00:00 EDT 1994 · Journal of the Electrochemical Society; (United States)

DOI:https://doi.org/10.1149/1.2054884· OSTI ID:7198757

Streinz, C C; Moran, P J ^[1]; Kruger, J ^[2]

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1. Naval Academy, Annapolis, MD (United States). Dept. of Mechanical Engineering
2. Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Materials Science and Engineering

Solid-solution Al-Ta alloys possess significantly higher pitting potentials than pure aluminum in Cl[sup [minus]] solutions. Dynamic imaging microellipsometry was used to study the passive film formation on solid solution Al-Ta alloys. Film thickness was measured during growth for alloy compositions of pure Al, Al-8 a/o Ta, Al-25 a/o Ta, and pure Ta at applied potentials of 0.0, 1.0, 2.0, and 5.0 V SCE in a pH 7.2 borate buffer. Increasing the concentration of tantalum resulted in the formation of thinner passive films at all applied potentials. On pure Al and Al-8 a/o Ta, precipitation of an Al(OH)[sub 3] type film results in a linearly increasing film thickness with time. The relationship of film thickness measurements to the enhanced localized corrosion resistance is discussed.

• OSTI ID: 7198757
• Journal Information: Journal of the Electrochemical Society; (United States), Journal Name: Journal of the Electrochemical Society; (United States) Vol. 141:5; ISSN JESOAN; ISSN 0013-4651
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
ALUMINIUM
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM HYDROXIDES
CHLORIDES
CHLORINE COMPOUNDS
COMPARATIVE EVALUATIONS
CORROSION PRODUCTS
CORROSIVE EFFECTS
ELEMENTS
ELLIPSOMETRY
EVALUATION
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXIDES
MEASURING METHODS
METALS
MICROANALYSIS
OXYGEN COMPOUNDS
PASSIVATION
TANTALUM
TANTALUM ALLOYS
TRANSITION ELEMENTS