High-temperature oxidation of Al-Mg alloys

Journal Article · Mon Oct 01 00:00:00 EDT 1990 · Oxidation of Metals; (USA)

DOI:https://doi.org/10.1007/BF00665021· OSTI ID:6118576

Zayan, M H ^[1]; Jamjoom, O M; Razik, N A ^[2]

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1. Ain Shams Univ., Cairo (Egypt)
2. King Abdulaziz Univ., Jeddah (Saudi Arabia)

Surface-analysis techniques (x-ray photoelectron spectroscopy and Auger electron spectroscopy) and electron microscopy (SEM and TEM) have been used to study the mechanism of steady-state high-temperature oxidation of Al-Mg alloys. Two high-purity alloys containing 0.4 and 2.0 wt.% Mg were heat-treated in dry air at 550C up to 90 hr. It was found that the oxide layer was composed of MgO and spinel (MgAl{sub 2}O{sub 4}), the major constituent being MgO. The molar concentration of MgO decreased with increasing depth, while that of spinel increased. The rate-controlling mechanism for the growth of the oxide layer in the Al-0.4Mg alloy was the solid-state diffusion of Mg in the MgO-spinel constituents. For alloys of higher-magnesium content, the growth of the oxide layer was controlled by solid-state diffusion of Mg through the adherent protective oxide areas and by the transport of Mg vapor across voids formed between the alloy substrate and the oxide layer.

• OSTI ID: 6118576
• Journal Information: Oxidation of Metals; (USA), Vol. 34:3-4, Issue 3-4; ISSN 0030-770X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
OXIDATION
MAGNESIUM ALLOYS
AUGER ELECTRON SPECTROSCOPY
EXPERIMENTAL DATA
HIGH TEMPERATURE
MAGNESIUM ADDITIONS
MEASURING METHODS
PHOTOELECTRON SPECTROSCOPY
SCANNING ELECTRON MICROSCOPY
TRANSMISSION ELECTRON MICROSCOPY
ALLOYS
ALUMINIUM ALLOYS
CHEMICAL REACTIONS
DATA
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
INFORMATION
MICROSCOPY
NUMERICAL DATA
SPECTROSCOPY
360105* - Metals & Alloys- Corrosion & Erosion