An analytical electron microscopy study of constituent particles in commercial 7075-T6 and 2024-T3 alloys
- Mobil Exploration and Producing Center, Farmers Branch, TX (United States). Material, Corrosion and Inspection Group
- Naval Research Lab., Washington, DC (United States)
- Lehigh Univ., Bethlehem, PA (United States). Dept. of Mechanical Engineering and Mechanics
To better understand the role of constituent particles in pitting corrosion, analytical electron microscopic studies were performed on the constituent particles in commercial 7075-T6 and 2024-T3 alloys. Five phases, namely, Al{sub 23}CuFe{sub 4} and amorphous SiO{sub 2} in 7075-T6 and Al{sub 2}CuMg, Al{sub 2}Cu, and (Fe,Mn){sub x}Si(Al,Cu){sub y} in 2024-T3, were identified. The crystal structure and chemistry of the Al{sub 23}CuFe{sub 4}, Al{sub 2}CuMg, and Al{sub 2}Cu phases in these alloys are in good agreement with the published data. Small deviations from their stoichiometric compositions were observed and are attributed to the influence of alloy composition on the phase chemistry. For the (Fe,Mn){sub x}Si(Al,Cu){sub y} (approximately, x = 3 and y = 11) phase, a rhombohedral structure, with lattice parameter a = b = c = 1.598 nm and {alpha} = {beta} = {gamma} = 75 deg, was identified and is believed to be a modified form of either Al{sub 8}Fe{sub 2}Si or Al{sub 10}Mn{sub 3}Si. Information from this study provided technical support for studying the electrochemical interactions between the individual particles (or phases) and the matrix. The corrosion results are reported in a companion article.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 616489
- Journal Information:
- Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 4 Vol. 29; ISSN 1073-5623; ISSN MMTAEB
- Country of Publication:
- United States
- Language:
- English
Similar Records
COMPRESSIVE AND TENSILE CREEP OF 7075-T6 AND 2024-T3 ALUMINUM-ALLOY SHEET
Local dissolution phenomena associated with S phase (Al{sub 2}CuMg) particles in aluminum alloy 2024-T3