Mullis, AM (2011) Prediction of the operating point of dendrites growing under coupled thermosolutal control at high growth velocity. Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 83 (6). 061601. ISSN 1539-3755
Abstract
We use a phase-field model for the growth of dendrites in dilute binary alloys under coupled thermosolutal control to explore the dependence of the dendrite tip velocity and radius of curvature upon undercooling, Lewis number (ratio of thermal to solutal diffusivity), alloy concentration, and equilibrium partition coefficient. Constructed in the quantitatively valid thin-interface limit, the model uses advanced numerical techniques such as mesh adaptivity, multigrid, and implicit time stepping to solve the nonisothermal alloy solidification problem for material parameters that are realistic for metals. From the velocity and curvature data we estimate the dendrite operating point parameter σ*. We find that σ* is nonconstant and, over a wide parameter space, displays first a local minimum followed by a local maximum as the undercooling is increased. This behavior is contrasted with a similar type of behavior to that predicted by simple marginal stability models to occur in the radius of curvature, on the assumption of constant σ*.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2011, American Physical Society. This is an author produced version of a paper published in Physical Review E - Statistical, Nonlinear, and Soft Matter Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Alloy concentration; alloy solidification; binary alloy solidification; columnar front; curvature data; equilibrium partition; fully implicit; high growth velocities; lewis numbers; local maximum; local minimums; marginal stability; material parameter; melts; mesh adaptivity; multi-grid; nonisothermal; numerical techniques; operating points; parameter spaces; pattern selection; phase-field models; radius of curvature; rapid solidification; simulation; spontaneous grain-refinement; thermosolutal; thin-interface limit; time-stepping; tip velocity; to-equiaxed transition |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) > Institute for Materials Research (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 03 Apr 2014 16:28 |
Last Modified: | 23 Jun 2023 21:38 |
Published Version: | http://dx.doi.org/10.1103/PhysRevE.83.061601 |
Status: | Published |
Publisher: | American Physical Society |
Identification Number: | 10.1103/PhysRevE.83.061601 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:78342 |