The effect of Ag additions on the microstructure of aluminium-lithium alloys

Citation
N. Boukos et al., The effect of Ag additions on the microstructure of aluminium-lithium alloys, J MATER SCI, 33(15), 1998, pp. 4015-4020
Citations number
32
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
JOURNAL OF MATERIALS SCIENCE
ISSN journal
00222461 → ACNP
Volume
33
Issue
15
Year of publication
1998
Pages
4015 - 4020
Database
ISI
SICI code
0022-2461(19980801)33:15<4015:TEOAAO>2.0.ZU;2-G
Abstract
Minor quantities of Ag have been added to Al-Li-Cu-Mg-Zr alloys. Their micr ostructure has been studied by means of optical metallography, transmission electron microscopy and X-ray diffraction. In the high Li, low Cu: Mg rati o alloys the main phases found were delta', beta', S' and T-1, while fewer T-2 and Al7Cu2Fe precipitates were also observed. The addition of up to 0.5 wt % Ag diminishes the delta' and T-1 precipitates size. This is attribute d to a small increase of Li solubility in the matrix. In the low Li, high C u:Mg ratio alloy the addition of 0.2 wt % Ag resulted in the precipitation of Omega phase simultaneously with delta', beta', S' and T-1 phases. Due to the low Li concentration an unusual growth of the delta'/beta' precipitate s at the expense of the delta' precipitates was also observed. (C) 1998 Klu wer Academic Publishers.