Article ID Journal Published Year Pages File Type
1448382 Acta Materialia 2010 17 Pages PDF
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 150 °C. 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 show that Cu–Mg clusters provide additional sites for vacancy stabilisation.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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