On the pitting resistance of sputter-deposited aluminum alloys

Journal Article · Sun Aug 01 04:00:00 EDT 1993 · Journal of the Electrochemical Society; (United States)

DOI:https://doi.org/10.1149/1.2220794· OSTI ID:6254294

Frankel, G S; Jahnes, C V; Russak, M A ^[1]; Newman, R C ^[2]

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1. IBM Research Div., Yorktown Heights, NY (United States). T.J. Watson Research Center
2. UMIST, Manchester (United Kingdom). Corrosion and Protection Centre

The pitting behavior of sputter-deposited Al binary alloy thin films was studied. Pitting and repassivation potentials were determined in 0.1M NaCl for samples in freshly deposited and air-aged states. Aging for several years in laboratory air increased the pitting potential for some of the alloy systems but had no effect on others The repassivation potentials, meaningful values for pits in thin films, were found to be very close to the pitting potentials of freshly-deposited films for many alloy systems. Stable pits initiate in these Al binary alloys a t potentials just above te value at which they would repassivate, indicating that pit growth considerations control the pitting process. By determining the pit anodic current density just before passivation it is shown that alloying improves pitting resistance through a reduction in the ability of pits to maintain the critical local environment necessary for growth. The influences of alloying on the passive film chemistry and on the tendency of the metal to repassivate (depassivation pH) are secondary in nature.

• OSTI ID: 6254294
• Journal Information: Journal of the Electrochemical Society; (United States), Journal Name: Journal of the Electrochemical Society; (United States) Vol. 140:8; ISSN JESOAN; ISSN 0013-4651
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALKALI METAL COMPOUNDS
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
BINARY ALLOY SYSTEMS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
COATINGS
CORROSION
CORROSION RESISTANCE
CURRENT DENSITY
DATA
DEPOSITION
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
INFORMATION
NUMERICAL DATA
PASSIVATION
PITTING CORROSION
SAMPLE PREPARATION
SODIUM CHLORIDES
SODIUM COMPOUNDS
SPUTTERING
SURFACE COATING
VACUUM COATING
VAPOR DEPOSITED COATINGS