About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
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Frontiers in Solidification: An MPMD Symposium Honoring Jonathan A. Dantzig
|
Presentation Title |
Quantitative Phase-field Modeling of Alloy Solidification Far from Equilibrium: New Insights into Absolute Stability and Banded Microstructures |
Author(s) |
Alain S. Karma, Kaihua Ji, Elaheh Dorari, Amy Clarke |
On-Site Speaker (Planned) |
Alain S. Karma |
Abstract Scope |
Quantitatively modeling of alloy solidification under far-from-equilibrium growth conditions relevant for additive manufacturing has remained a major challenge. Here, we present a novel fully variational phase-field formulation that copes with this challenge. The model reproduces known velocity-dependent forms of the partition coefficient and liquidus slope for different interface thicknesses, thereby enabling quantitative simulations on experimentally relevant length and time scales with a computationally tractable interface thickness over a three orders of magnitude velocity range spanning cm/sec to several m/sec. The model is applied to binary metallic alloys and shown to reproduce for the first time the transition from cellular/dendritic to banded microstructures near the absolute stability limit. The model sheds new light on the mechanisms controlling the absolute stability limit and banded microstructure formation. The predictions are in good quantitative agreement with DTEM observations in thin Al-Cu films. |
Proceedings Inclusion? |
Planned: |
Keywords |
Additive Manufacturing, Solidification, Aluminum |