| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Factors Controlling Heteroepitaxial Phase Formation at Intermetallic-Al3Sc/Liquid Interfaces |
| Author(s) |
Hunter Wilkinson, Brianne Boyd, Deep Choudhuri |
| On-Site Speaker (Planned) |
Deep Choudhuri |
| Abstract Scope |
The mechanism of face-centered-cubic (FCC)-Al formation at an L12-Al3Sc/liquid-Al interface was investigated by using ab initio molecular dynamics. We compared the relative stability of (001)Al3Sc/liquid-Al and (111)Al3Sc/liquid-Al interfaces and examined their effect on the heterogeneous nucleation of FCC-Al. Enhanced interfacial bonding along [001]Al3Sc stabilized the (001)Al3Sc/liquid-Al, and formed in-liquid ordered layer resembling (002)FCC. Subsequently, the (001)Al3Sc/liquid-Al interface was subjected to stepwise cooling from 1450 to 950 K. The (002)-ordered layer was found to promote layer-by-layer epitaxial growth of FCC-coordinated regions to ~25%fraction. During cooling, the resulting misfit strains—at (001)Al3Sc/(002)-ordered layer and (001)Al3Sc/(002)FCC-Al interface ranged from -7.4 to 0.5\% within 950-1450K. Magnitude of such misfit strains reduced significantly between 1250 and 950 K, and this trend coincided with a sharp increase in FCC. Our study showed that heteroepitaxial formation of FCC-Al on the (001)-faces of intermetallic Al3Sc, and that this mechanism is closely associated with a reduction in misfit strains. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Aluminum, Phase Transformations |