Abstract
The –Al
Cu phase in an Al–4Zn–2Cu–1Mg–0.7Si (wt.%) alloy was investigated by means of scanning transmission electron microscopy. With our specific alloy composition, the phase is often formed with stacking faults on
and
planes. The stacking faults on
planes are often regularly spaced and create a previously unreported superstructure. Structural damage by electron irradiation is observed, even at a low acceleration voltage of 80 kV. The damage is more pronounced in the
precipitates with stacking faults, which agrees with theoretical calculations of knock-on scattering cross-sections. These two very different forms of disruptions of the
structure are linked to its spacious interstitial sites and the ease at which Cu atoms diffuse into and between them.
Acknowledgements
The authors would like to thank the Research Council of Norway (RCN) for funding of the FRINATEK project “Fundamental investigations of precipitation in the solid state with focus on Al-based alloys”.
Notes
No potential conflict of interest was reported by the authors.