Natural ageing behaviour in Al-Cu alloys containing Sc and Z
Loading...
Date
2021-11-24
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Australian Nuclear Science and Technology Organisation
Abstract
The 2xxx series Al-Cu alloys have been extensively used as engineering structures and components of lightweight vehicles due to their excellent strength-to-weight ratio. Recent research has demonstrated that further substantial enhancement in the strength of Al-Cu alloys could be achieved by adding Sc and Zr by forming nano-sized Al3(Sc, Zr) dispersoids. However, further development and manufacturing of these new Sc and Zr-containing Al-Cu alloys are limited by a lack of basic understanding of the effect of Al3(Sc, Zr) dispersoids on the microstructural evolution during room temperature storage after quenching from solution treatment (called natural ageing). In this work, therefore, we have studied the effect of Al3(Sc, Zr) dispersoids on natural ageing behaviour in an Al-4wt.%Cu-0.1wt.%Sc-0.1wt.%Zr alloy using small-angle neutron and x-ray scattering (SANS and SAXS). The hardness measurement shows that the presence of Al3(Sc, Zr) dispersoids significantly delays the natural ageing kinetics of Al-Cu alloys. SANS was used to quantify the size distribution of Al3(Sc, Zr) dispersoids which is ~ 25 ± 3 nm. In-situ SAXS results show that the presence of Al3(Sc, Zr) dispersoids results in a significant delay in the solute clustering formation during natural ageing. This is attributed to the suppression of the natural ageing kinetics in the Al-Cu-Sc-Zr alloys. These results were confirmed by differential scanning calorimetry (DSC) and high resolution transmission electron microscopy (TEM). The suppression mechanism is hypothesized to come from the dispersoids and Sc solute acting as vacancy sinks which slows down the diffusion of solute at room temperatures. © 2021 The Authors
Description
This is an oral presentation only.
Keywords
Strain aging, Alloys, Zirconium, Aluminium, Sulfur, Scattering, Small angle scattering
Citation
Jiang, L., Wood, K., Knott, R., Sokolova, A., & Dorin, T. (2021). Natural ageing behaviour in Al-Cu alloys containing Sc and Z. Presentation to the ANSTO User Meeting, Online, 24-26 November 2021. Retrieved from: https://events01.synchrotron.org.au/event/146/contributions/4252/