The solidification of a dilute alloy (bismuth-tin) under Bridgman crystal growth conditions is investigated in support of NASA's MEPHISTO space shuttle flight experiment. Computations are performed in two-dimensions with a uniform grid. The simulation includes the species-concentration, temperature and flow fields, as well as conduction in the ampoule. Fully transient simulations have been performed; no simplifying steady state approximations are used. Results are obtained under microgravity conditions for pure bismuth, and Bi-0.1 at.%Sn and Bi-1.0 at.%Sn alloys. The concentration dependence of the melting temperature is neglected; the solid/liquid interface temperature is assumed to be the melting temperature of pure bismuth for all cases studied. For the Bi-1.0at.%Sn case the results indicate that a secondary convective cell, driven by solutal gradients, forms near the interface. The magnitude of the velocities in this cell increases with time; this causes increasing solute segregation at the solid/liquid interface.


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Melt convection effects in the Bridgman crystal growth of an alloy under microgravity conditions


    Contributors:


    Publication date :

    1998


    Size :

    10 Seiten, 16 Quellen


    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Study of Bridgman Crystal Growth Process under Microgravity

    Chien, L.-C. / Chang, W.-T. / AIAA | British Library Conference Proceedings | 1994


    Study of Bridgman Crystal Growth Process Under Microgravity

    Chien, L.-C. / Chang, W.-T. / AIAA | British Library Conference Proceedings | 1994


    Theoretical Analysis of 3D, Transient Convection and Segregation in Microgravity Bridgman Crystal Growth

    Yeckel, A. / de Almeida, V. F. / Derby, J. J. et al. | British Library Conference Proceedings | 2000



    Theoretical analysis of 3D, transient convection and segregation in microgravity Bridgman crystal growth

    Yeckel, Andrew / de Almeida, Valmor F. / Derby, Jeffrey J. | American Institute of Physics | 2000