| Summary: | 碩士 === 國立成功大學 === 工程科學系碩博士班 === 91 === In the process of solidification, the variations of the temperature and concentration fields will directly affect the microstructures of materials, which have very close relations with the qualities of materials. This paper is to build two models to study the cellular shape of constrained growth. The first model, based on the Scheil equation with forward diffusion, was set up. This model includes the solute diffusion and the capillarity effect. The second model is a complete one, which consists of the concentration and temperature fields, and the effects of capillarity effect and atom attachment. In the second model, the shape of the solid/liquid interface of cellular growth is not known a priori, rather it is calculated as part of solution to the field problem. The cellular shape predicted by the first model will be used as the initial shape of the second model. The direct iteration method was used to compute the self-consistent cellular shape. With these models, the effects of different control parameters, which are growth rate, temperature gradient and the initial concentration, were investigated. It is hoped that the results of this study can be referred to for the further study.
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