• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Numerical simulation of dendritic growth of binary alloys

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_3060936_sip1_m.pdf
    Size:
    3.937Mb
    Format:
    PDF
    Download
    Author
    Zhao, Pinghua
    Issue Date
    2002
    Keywords
    Engineering, Mechanical.
    Advisor
    Heinrich, Juan C.
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    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.
    Abstract
    A two-dimensional finite element model for simulation of dendritic solidification of binary alloys is developed. The model solves the coupled time-dependent temperature and solute concentration equations on two independent meshes: a fixed mesh for the temperature and an adaptive interface-conforming mesh for the concentration. The temperature is solved on the whole domain while the concentration is solved only on the liquid region because diffusion in the solid is much smaller than that in the liquid and can be neglected. Temperature and concentration are coupled at the interface through the generalized Gibbs-Thompson relation. The solid-liquid interface is explicitly tracked with a set of marker points that defines its position at all times. Latent heat of fusion, interfacial energy, kinetic mobility and crystalline anisotropy are taken into account. The adaptive mesh is generated at every time step as the interface position changes. The model is easy to use in the sense that it works with physical variables as opposed to those based on the phase-field variable and level-set method. The model is very accurate as demonstrated by a series of calculations that compare to exact solutions or predictions by solidification theories. In simulations of solidification of pure materials, where only the energy equation is solved, the model produces very complicated dendritic structures that are in close agreement with experimental observations, and the computation is very efficient. Calculations under a variety of conditions show that the undercooling and surface tension are the main factors that determine the final dendritic structures. In simulations of alloy solidification, where both the energy and solutal concentration equations are solved, the results for the onset of interface instability and the prediction of the most unstable wavelength are in good agreement with linear stability theory. When applied to simulations of directional solidification of Pb-Sb alloys, the model generates dendritic structures and solute segregation similar to those observed experimentally, and the interface-development from a planar form to cells to dendritic structures is clearly demonstrated. These simulations are the first of their kind.
    Type
    text
    Dissertation-Reproduction (electronic)
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Graduate College
    Aerospace and Mechanical Engineering
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.