Please use this identifier to cite or link to this item:
http://hdl.handle.net/11375/6175
Title: | Cellular Instability in Binary Solidification |
Authors: | Venugopalan, Devarajan |
Advisor: | Kirkaldy, J.S. |
Department: | Metallurgy |
Keywords: | Metallurgy;Metallurgy |
Publication Date: | Aug-1982 |
Abstract: | <p>The steady-state growth of cells in binary alloy single phase solidification is examined theoretically and experimentally. The failure of the marginal-stability calculations to predict and describe the growth of stable cells indicates a theoretical gap in this field. The Zener-Hillert type model for cellular solidification proposed by Kirkaldy is discussed. In this theory the physics of cell growth demands that the interface be a non-equilibrium interface stabilized by Kinetic and crystallographic effects. A quantitative model following this line is advanced for the steady-state growth of two-dimensional cells. The solution to the free boundary diffusion problem requires, in addition to the boundary conditions, two extra constraints. A principle of minimum cell root radius, surrogate to the principle of minimum rate of entropy production, is used to provide the additional conditions. Cell growth in the succinonitrile-salol system was studied experimentally. For a given set of growth conditions the cells have a unique steadystate spacing and length. Perturbation experiments about the steady-state support the validity of the optimization procedure used in the calculations. Quantitative predictions on steady-state growth are verified by the experiments.</p> |
URI: | http://hdl.handle.net/11375/6175 |
Identifier: | opendissertations/1505 2188 1265700 |
Appears in Collections: | Open Access Dissertations and Theses |
Files in This Item:
File | Size | Format | |
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fulltext.pdf | 2.22 MB | Adobe PDF | View/Open |
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