Jackson, Gilmer and Temkin used a Spin-1 kinetic Ising model to simulate non-equilibrium binary alloy solidification. In this dissertation the detailed relationship of this model to the solidification of binary alloys is reported. The phase transformation kinetics of the model is investigated as a function of growth rate, surface roughness, liquid diffusivity, equilibrium segregation coefficient, entropy of fusion, and composition of the liquid. Simulations for pure silicon predict a growth rate dependence on orientation and undercooling in accord with experimental results. Simulation results for the binary material show an increase in the non-equilibrium segregation coefficient (k(neq)) with surface smoothness, growth velocity and decreasing liquid diffusivity. Simulations for the orientation and growth velocity dependence of the segregation coefficient are in accord for experimental results for the solidification of bismuth doped silicon due to Aziz et al. Simulation results on the dependence of k(neq) on the equilibrium segregation coefficient, k(eq) are also consistent with experiment. The non-equilibrium segregation coefficient was found to increase with concentration of the liquid, but the effect is small at low concentrations.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/288738 |
| Date | January 1997 |
| Creators | Beatty, Kirk Matthew, 1962- |
| Contributors | Jackson, Kenneth A. |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Dissertation-Reproduction (electronic) |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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