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Interface Pattern Selection in Directional SolidificationThe central focus of this research is to establish key scientific concepts that govern the selection of cellular and dendritic patterns during the directional solidification of alloys. Ground-based studies have established that the conditions under which cellular and dendritic microstructures form are precisely where convection effects are dominant in bulk samples. Thus, experimental data can not be obtained terrestrially under pure diffusive regime. Furthermore, reliable theoretical models are not yet possible which can quantitatively incorporate fluid flow in the pattern selection criterion. Consequently, microgravity experiments on cellular and dendritic growth are designed to obtain benchmark data under diffusive growth conditions that can be quantitatively analyzed and compared with the rigorous theoretical model to establish the fundamental principles that govern the selection of specific microstructure and its length scales. In the cellular structure, different cells in an array are strongly coupled so that the cellular pattern evolution is controlled by complex interactions between thermal diffusion, solute diffusion and interface effects. These interactions give infinity of solutions, and the system selects only a narrow band of solutions. The aim of this investigation is to obtain benchmark data and develop a rigorous theoretical model that will allow us to quantitatively establish the physics of this selection process.
Document ID
20010057323
Document Type
Conference Paper
Authors
Trivedi, Rohit (Iowa State Univ. of Science and Technology Ames, IA United States)
Tewari, Surendra N. (Cleveland State Univ. Cleveland, OH United States)
Date Acquired
August 20, 2013
Publication Date
March 1, 2001
Publication Information
Publication: Microgravity Materials Science Conference 2000
Volume: 3
Subject Category
Chemistry and Materials (General)
Funding Number(s)
CONTRACT_GRANT: NCC8-98
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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