| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
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| Symposium
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Progress towards Understanding the Synthesis and Behavior of Metals Far from Equilibrium: A SMD Symposium Honoring Enrique Lavernia on the Occasion of His 60th Birthday
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| Presentation Title |
Time-Resolved Characterization of Far-from-equilibrium Microstructure Evolution During Rapid Solidification |
| Author(s) |
Joseph McKeown, John D Roehling, Tian Li, Alexander A Baker, Scott K McCall, Kai Zweiacker, Amy J Clarke, Jörg Wiezorek |
| On-Site Speaker (Planned) |
Joseph McKeown |
| Abstract Scope |
The dynamic transmission electron microscope (DTEM) at Lawrence Livermore National Laboratory (LLNL) was developed to enable in situ multi-frame image acquisitions (i.e., movies) of rapidly evolving, far-from-equilibrium materials processes with nanometer spatial and nanosecond temporal resolutions. Here, work will be presented from laser-induced rapid solidification (RS) experiments in Al-based alloys. RS occurs in numerous manufacturing processes involving metallic alloys, such as laser welding and additive manufacturing (AM), and results in processing conditions (large thermal gradients, high cooling rates and solidification front velocities) that produce highly non-equilibrium microstructures. DTEM allows direct observation of RS microstructure evolution and measurements of kinetics. The effects of solute species (Cu, Ag, Ce), temperature gradient, and solidification rate on phase selection and morphology will be presented, with complementary in situ heat treatments to assess thermal stability of RS microstructures and ex situ postmortem microstructure evaluation. |
| Proceedings Inclusion? |
Undecided |