Accession Number:

ADA073096

Title:

AUGER ELECTRON SPECTROSCOPY STUDIES OF OXIDE FILMS ON AL-ZN-MG ALLOYS,

Descriptive Note:

Corporate Author:

MARTIN MARIETTA LABS BALTIMORE MD

Report Date:

1979-07-01

Pagination or Media Count:

17.0

Abstract:

Auger electron spectroscopy and depth profiling have been used to obtain information on the composition of oxide films formed on high purity Al-5.5Zn-2.5Mg alloys as a function of heat treatment, grain size, storage environment and temperature. These studies show that in the as-heat-treated condition the oxide film is predominantly MgO. The MgO peak-to-peak height ratio of this oxide is sensitive to the heat treatment temperature and exhibits a maximum at 475 C. During subsequent storage, especially in a moist environment, this film undergoes substantial changes in composition. The MgAl ratio of the oxide decreases due to formation of an Al-rich oxide on top of the as-heat-treated oxide. A model is proposed to account for the changes in the oxide film composition during growth of the Al-rich oxide, and possible implications to pre-exposure embrittlement and stress corrosion cracking are discussed. Author

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy
  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE