About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Frontiers in Solidification: An MPMD Symposium Honoring Jonathan A. Dantzig
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Presentation Title |
In-situ Measurements of Dendrite Tip Shape Selection in a Metallic Alloy |
Author(s) |
Christoph Beckermann, Hieram Neumann-Heyme, Natalia Shevchenko, Joerg Grenzer, Kerstin Eckert, Sven Eckert |
On-Site Speaker (Planned) |
Christoph Beckermann |
Abstract Scope |
The size and shape of the primary dendrite tips determine the principal length scale of the microstructure evolving during solidification of alloys. In-situ X-ray measurements of the tip shape in metals have been unsuccessful so far due to insufficient spatial resolution or high image noise. To overcome these limitations, high-resolution synchrotron radiography and advanced image processing techniques are applied to a thin sample of a solidifying Ga-35wt.%In alloy. Quantitative in-situ measurements are performed of the growth of dendrite tips, with tip velocities ranging over almost two orders of magnitude. The value of the dendrite tip shape selection parameter is found to be σ*=0.0768, which suggests an interface energy anisotropy of ε4=0.015 for the present Ga-In alloy. The non-axisymmetric dendrite tip shape amplitude coefficient is measured to be A4=0.004, which is in excellent agreement with the universal value previously established for dendrites. |
Proceedings Inclusion? |
Planned: |
Keywords |
Solidification, |