The evolution of atomistic-level nanostructure during the early stages of elevated temperature ageing of rapid hardening (RH) Al-Cu-Mg alloys has been characterised by a combination of atom probe tomography (APT), transmission electron microscopy (TEM) and positron annihilation spectroscopy (PAS). APT analysis confirms that significant dispersions of small solute clusters form during ageing for 60 s at 150ºC. No zone-like precipitate structures were observed by TEM and APT examinations. These small clusters are believed to be responsible for the RH effect. Careful quantitative APT analysis reveals that a high density of Cu-Mg clusters with high Mg:Cu ratio gives the most potent strengthening response. Positron annihilation measurements also how that Cu-Mg clusters provide additional sites for vacancy stabilisation.

Solute clustering in Al–Cu–Mg alloys during the early stages of elevated temperature ageing

FERRAGUT, RAFAEL OMAR;DUPASQUIER, ALFREDO;
2010-01-01

Abstract

The evolution of atomistic-level nanostructure during the early stages of elevated temperature ageing of rapid hardening (RH) Al-Cu-Mg alloys has been characterised by a combination of atom probe tomography (APT), transmission electron microscopy (TEM) and positron annihilation spectroscopy (PAS). APT analysis confirms that significant dispersions of small solute clusters form during ageing for 60 s at 150ºC. No zone-like precipitate structures were observed by TEM and APT examinations. These small clusters are believed to be responsible for the RH effect. Careful quantitative APT analysis reveals that a high density of Cu-Mg clusters with high Mg:Cu ratio gives the most potent strengthening response. Positron annihilation measurements also how that Cu-Mg clusters provide additional sites for vacancy stabilisation.
2010
Aluminium alloys; Age hardening; Solute clustering; Atom probe tomography; Positron annihilation
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/523508
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