About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
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Materials Design Approaches and Experiences V
|
Presentation Title |
Non-equilibrium Interfacial Solute Segregation as a Thermal Stabilization Mechanism in Al-Cu Alloys |
Author(s) |
Amit Shyam, Dongwon Shin, Jonathan Poplawsky, James Morris, Patrick Shower, Lawrence Allard, Matthew Chisholm, Thomas Watkins, Sumit Bahl, Allen Haynes |
On-Site Speaker (Planned) |
Amit Shyam |
Abstract Scope |
In this presentation, we identify a non-equilibrium interfacial solute segregation (NEISS) mechanism in Al-Cu alloy microstructures that imparts increased thermal stability of the metastable θʹ phase over the thermodynamically stable θ phase. The NEISS mechanism can be implemented in Al-Cu alloy microstructures through microalloying elements that have diffusion coefficients lower than Cu, and that have a driving force for segregating to critical interfaces between the θʹ and the matrix. Through examples from the Al-Cu-Mn-Zr (ACMZ) alloy system, where θʹ precipitates are stable up to 350oC, it will be demonstrated that the NEISS mechanism effectively improves the thermal stability of θʹ precipitates. It will be further demonstrated that density functional theory calculations are a useful tool to identify elements that possess a thermodynamic driving force to segregate to the critical interfaces. It will be shown that this mechanism can be applied to progressively stabilize or “rejuvenate” precipitation hardened alloy systems. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |