Abstract
The role of Ag in the pre-precipitation process of an Al-1.9at.%Cu- 0.3 at.% Mg-0.2at.% Ag alloy has been investigated in view of the interaction between the quenched-in vacancies and Ag atoms. Positron annihilation methods, coincidence Doppler broadening of positron annihilation radiation and positron lifetime spectroscopies, and transmission electron microscopy have been employed. In an as-quenched state, quenched-in vacancies V in the Al- 1.9at.%Cu-0.3at.%Mg~0.2at.%Ag alloy are associated with Ag atoms as well as Mg atoms (V-Mg-Ag) while V-Mg complexes are formed in the A1 1.9at.%Cu-0.3at.%Mg alloy. The recovery of the vacancies after 15s ageing at 180°C is suppressed by the existence of Ag atoms. These results indicate that the V-Mg complexes are stabilized by the associated Ag atoms, which promotes the co-clustering of Ag and Mg atoms by ageing rather than by the formation of dislocation loops.
Original language | English |
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Pages (from-to) | 1559-1572 |
Number of pages | 14 |
Journal | Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties |
Volume | 82 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2002 May |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Condensed Matter Physics
- Physics and Astronomy (miscellaneous)
- Metals and Alloys