Model for nonprotective oxidation of Al-Mg alloys

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Oxidation of Metals; (USA)

DOI:https://doi.org/10.1007/BF00664426· OSTI ID:6364370

Zayan, M H ^[1]

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1. Ain Shams Univ., Cairo (Egypt)

The oxidation of Al-5Mg alloy has been studied at 550 C in dry air. Morphological details of the MgO layers which develop on this alloy during high-temperature oxidation have been studied by scanning electron microscopy (SEM). A localized detachment of the protective, adherent MgO layer was found, which is caused by voids formed by vacancy condensation at the metal-oxide interface. The source of these vacancies was the outward diffusion of Mg though the oxide layer. Continuing growth of these voids was responsible for cracking of oxide ridges and nodules, as well as the growth of new MgO having a cauliflower morphology. A model describing the process of the outward diffusion is given.

• OSTI ID: 6364370
• Journal Information: Oxidation of Metals; (USA), Vol. 34:5-6; ISSN 0030-770X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
OXIDATION
MAGNESIUM ALLOYS
EXPERIMENTAL DATA
HIGH TEMPERATURE
MAGNESIUM OXIDES
MEASURING METHODS
SCANNING ELECTRON MICROSCOPY
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
ALUMINIUM ALLOYS
CHALCOGENIDES
CHEMICAL REACTIONS
DATA
ELECTRON MICROSCOPY
INFORMATION
MAGNESIUM COMPOUNDS
MICROSCOPY
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
360105* - Metals & Alloys- Corrosion & Erosion