About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Aluminum Alloys: Development and Fabrication Symposium and Supplier Forum
|
| Presentation Title |
Controlling Fe-rich Intermetallics in Al-Si casting alloys with high Fe content via melt thermal history |
| Author(s) |
Young-Hee Cho, Hyeon-Seok Cheon, Su-Hyeon Kim, Hyeon-Woo Son, Seung-Uk Lee, Kwangjun Euh, Je In Lee |
| On-Site Speaker (Planned) |
Young-Hee Cho |
| Abstract Scope |
Fe impurities at recycling-relevant levels promote brittle, plate-like β-Al₅FeSi intermetallics that limit the performance of Al–Si casting alloys. We demonstrate that melt thermal history can govern Fe-rich intermetallic phase selection in an A356 (Al-7Si-0.35Mg) alloy containing 0.4 wt% Fe. Thermal-rate treatment (TRT), involving melt superheating to 800 °C for 60 min prior to solidification, suppresses monoclinic β-Al₅FeSi and promotes metastable cubic α-AlFeSi with a Chinese-script morphology across cooling rates from gravity casting to melt spinning without additives. Atom probe tomography on rapidly solidified specimens reveals that TRT suppresses Fe-Si solute clustering, yielding a more homogeneous solute configuration in the melt. Partial radial distribution function analysis shows a pronounced reduction in Fe-Si correlations, indicating weakened chemical short-range order in the liquid state. This homogenized solute configuration facilitates preferential α-AlFeSi nucleation, while diffusion-limited kinetics at elevated cooling rates inhibit the subsequent peritectic α-to-β transformation during solidification. |
| Proceedings Inclusion? |
Planned: Light Metals |
| Keywords |
Aluminum, Characterization, Solidification |