| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Metastable Phases and Phase Equilibria: Towards Designing the Next Generation of Alloys
|
| Presentation Title |
Pseudo-in situ Characterization of Phase Transformation in an Al-Cu-Mn-Zr Alloy using Atom Probe Tomography |
| Author(s) |
Bharat Gwalani, Elizabeth J. Kautz, Amit Shyam, Jonathan Poplawsky, Arun Devaraj |
| On-Site Speaker (Planned) |
Bharat Gwalani |
| Abstract Scope |
Aluminum (Al) alloys with improved high-temperature mechanical properties (up to 350oC) are needed to enable the next generation of higher efficiency, affordable vehicle engines. A significant challenge with traditional Al alloys is that at high temperatures the metastable, semi-coherent θ’(Al2Cu) transforms to θ(Al2Cu), the presence of which deteriorates mechanical properties. The compositionally optimized Al-Cu-Mn-Zr (ACMZ) alloys can be used at >325oC by utilizing an enveloping co-precipitation around θ’(Al2Cu) precipitates to extend the θ’ metastability. These co-precipitates could underpin the development of higher performance alloys (375-400oC). The current study focuses on characterization of coherent and incoherent interfacial changes, both compositional and structural, at fcc(matrix)- phase interfaces while aging. To have a detailed understanding of the coprecipitation mechanism, a novel in situ-atom probe tomography (APT) technique coupled with transmission electron microscopy (TEM) were used to probe early stage aging at 300 oC in an ultra-high vacuum environment. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |