Use of in situ atomic force microscopy to image corrosion at inclusions

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Journal of the Electrochemical Society; (United States)

DOI:https://doi.org/10.1149/1.2054943· OSTI ID:7248681

Rynders, R M; Paik, C H; Ke, R; Alkire, R C ^[1]

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1. Univ. of Illinois, Urbana, IL (United States)

In situ atomic force microscopy was used in conjunction with microlithography and scanning Auger electron spectroscopy to monitor localized corrosion near iron-rich inclusions in Al-6061-T6 immersed in 0.6M NaCl and also sulfur-rich inclusions in 304 stainless steel (SS-304) in 0.5M NaCl. The local rate of aluminum corrosion was found to depend on the shape of the nearby iron-rich inclusion. At the corrosion potential, trenches were observed to form in the aluminum host matrix adjacent to the inclusions, and the corrosion sites gradually evolved into circular shapes owing to dissolution. During the dissolution process, the width of the dissolution area was an order of magnitude greater than the depth. Application of a 400 mV cathodic overpotential prevented corrosion initiation, while application of a 500 mV cathodic overpotential greatly accelerated the dissolution rate in comparison with that at the rest potential. On SS-304, exposure to 0.5M NaCl was accompanied by formation of deposits, which decorated the inclusion surface as well as the surrounding area up to four times the radius of the original inclusion.

• DOE Contract Number: FG02-91ER45439
• OSTI ID: 7248681
• Journal Information: Journal of the Electrochemical Society; (United States), Journal Name: Journal of the Electrochemical Society; (United States) Vol. 141:6; 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
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
AUSTENITIC STEELS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
CORROSION
CORROSION RESISTANT ALLOYS
CORROSIVE EFFECTS
ELECTRON MICROSCOPY
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HIGH ALLOY STEELS
INCLUSIONS
IRON
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
METALS
MICROSCOPY
NICKEL ALLOYS
NONMETALS
SODIUM CHLORIDES
SODIUM COMPOUNDS
STAINLESS STEEL-304
STAINLESS STEELS
STEEL-CR19NI10
STEELS
SULFUR
TRANSITION ELEMENTS