Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-08T07:57:24.148Z Has data issue: false hasContentIssue false

A Reassessment of the Metastable Miscibility Gap in Al-Ag Alloys by Atom Probe Tomography

Published online by Cambridge University Press:  14 November 2007

Emmanuelle A. Marquis
Affiliation:
Materials Physics Department, Sandia National Laboratories, P.O. Box 969, MS 9161, Livermore, CA 94550, USA
Get access

Abstract

The evolution of Guinier-Preston zones in an Al-2.7 at.% Ag alloy was studied using atom probe tomography. The composition and morphology of the GP zones are time dependent, explaining discrepancies in previous work. This result requires the metastable miscibility gap for GP zones to be reevaluated, highlighting the importance of the temporal evolution of the GP zones. Preliminary results on the composition of γ′ and γ plates are also presented.

Type
Research Article
Copyright
© 2007 Microscopy Society of America

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Alexander, K.B., Legoues, F.K., Aaronson, H.I. & Laughlin, D.E. (1984). Faceting of GP zones in an Al-Ag alloy. Acta Metall 32, 22412249.CrossRefGoogle Scholar
Al-Kassab, T. & Haasen, P. (1993). Early stages of precipitation in dilute Al-Ag alloys. Zeitschrift fur Metallkunde 84, 248250.Google Scholar
Asta, M. & Hoytt, J.J. (2000). Thermodynamic properties of coherent interfaces in fcc-based Ag-Al alloys: A first-principles study. Acta Mater 48, 10891096.CrossRefGoogle Scholar
Baur, R. & Gerold, V. (1962). The existence of a metastable miscibility gap in aluminium-silver alloys. Acta Metall 19, 637645.CrossRefGoogle Scholar
Bischoff, G., Groger, V., Krexner, G. & Nieminen, R.M. (1996). Investigation of the composition and structure of GP zones in Al-Ag by means of positron annihilation. J Phys Condens Matter 8, 75237537.CrossRefGoogle Scholar
Dubey, P.A., Schonfeld, B. & Kostorz, G. (1991). Shape and internal structure of Guinier-Preston zones in Al-Ag. Acta Metall Mater 39, 11611170.CrossRefGoogle Scholar
Erni, R. (2003). Atomic-scale analysis of precipitates in Al-3 at.%Ag: Transmission electron microscopy. Ph.D. thesis. Zurich: Swiss Federal Institute of Technology.
Erni, R., Heinrich, H. & Kostorz, G. (2003). On the internal structure of Guinier-Preston zones in Al-3 at.% Ag. Phil Mag Lett 83, 599609.CrossRefGoogle Scholar
Ernst, F. & Haasen, P. (1987). The decomposition kinetics of Al-1 at%Ag at 413K studied by HREM. Phys Stat Sol 104, 404416.Google Scholar
Gragg, J.E. & Cohen, J.B. (1971). The structure of Guinier-Preston zones in aluminum-5at.% silver. Acta Metall 19, 507519.Google Scholar
Guinier, A. (1942). Le mécanisme de la precipitation dans un cristal de solution solide métallique. J Phys 3, 124136.Google Scholar
Guinier, A. (1996). On the birth of GP zones. Mater Sci Forum 3, 217222.CrossRefGoogle Scholar
Hellman, O.C., Vandenbroucke, J.A., Rusing, J., Isheim, D. & Seidman, D.N. (2000). Analysis of three-dimensional atom-probe data by the proximity histogram. Microsc Microanal 6, 437444.Google Scholar
Howe, J.M., Aaronson, H.I. & Gronsky, R. (1985). Atomic mechanisms of precipitate plate growth in the Al-Ag system—II. High resolution transmission electron microscopy. Acta Metall 33, 639648.Google Scholar
Howe, J.M. & Gronsky, R. (1986). Quantitative energy-dispersive X-ray analyses of γ′ precipitates in an Al-4.2 at.% Ag alloy. Scripta Metall 20, 11651168.CrossRefGoogle Scholar
Komiya, Y., Hirosawa, S. & Sato, T. (2006). 3DAP nano-scale analysis of solute clusters formed in naturally aged Al-Zn alloys. J Jpn Inst Light Metals 56, 662666.CrossRefGoogle Scholar
Legoues, F.K., Wright, R.N., Lee, Y.W. & Aaronson, H.I. (1984). Influence of crystallography upon critical nucleus shapes and kinetics of homogeneous fcc-fcc nucleation—V. The origin of GP zones in Al-Ag and Al-Cu alloys. Acta Metall 32, 18651870.Google Scholar
Malik, A., Shonfeld, B., Kostorz, G. & Pedersen, J.S. (1996). Microstructure of Guinier-Preston zones in Al-Ag. Acta Mater 44, 48454852.CrossRefGoogle Scholar
Massalski, T.B. (1990). Binary Alloy Phase Diagrams, 2nd ed., vol. 1. Warrendale, PA: ASM International.
Miller, M.K., Cerezo, A., Hetherington, M.G. & Smith, G.D.W. (1996). Atom Probe Field Ion Microscopy. Monographs on the Physics and Chemistry of Materials, Vol. 52. Oxford: Oxford University Press.
Naudon, A. & Caisson, J. (1974). Etude de la Lacune de miscibilité métastable et de la structure cristallographique des zones G.P. dans les alliages Aluminium-Argent. J Appl Cryst 7, 2536.Google Scholar
Nicholson, R.B. & Nutting, J. (1961). The metallography of precipitation in an Al-16% Ag alloy. Acta Metall 9, 332343.CrossRefGoogle Scholar
Osamura, K. & Nakamura, T. (1986). An AP-FIM study of metastable phases in Al-Ag binary alloy. Acta Metal 34, 15631570.CrossRefGoogle Scholar
Osamura, K., Nakamura, T., Kobayashi, A., Hashizume, T. & Sakurai, T. (1987). Chemical composition of GP zones in Al-Ag alloys. Scripta Metall 21, 255258.CrossRefGoogle Scholar
Vaumousse, D., Cerezo, A. & Warren, P.J. (2002). A procedure for quantification of precipitate microstructures from three-dimensional atom probe data. Ultramicroscopy 95, 215221.Google Scholar

Marquis

Figure 11. GP zones, a (gamma)' plate and the Ag-depleted zone around it

Download Marquis(Video)
Video 5.2 MB