Solidification process of highly undercooled bulk melts.
نویسندگان
چکیده
منابع مشابه
Non-Equilibrium Solidification of Undercooled Metallic Melts
If a liquid is undercooled below its equilibrium melting temperature an excess Gibbs free energy is created. This gives access to solidification of metastable solids under non-equilibrium conditions. In the present work, techniques of containerless processing are applied. Electromagnetic and electrostatic levitation enable to freely suspend a liquid drop of a few millimeters in diameter. Hetero...
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As suggested by Frank [1] an icosahedral short-range order should be energetically favoured in undercooled metallic melts. Such a short-range order is predicted to influence the energy of the interface between the liquid and a solid nucleus, depending on the structure of the solid phase [2]. This in turn decisively impacts the nucleation behaviour of solid phases from the undercooled melt, and ...
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This paper describes the results of experiments on metal droplet undercooling, and presents a preliminary analysis of the structures obtained. Work was conducted with Sn-25wt%Pb and Ni-34wt%Sn alloys. To achieve the required high degrees of undercooling, emuls i fication treatments were utilized following techniques described-by Perepezko and co-workers. Experiments show the fraction of supersa...
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The limits of validity of Ostwald’s rule of stages are investigated theoretically in the case of crystallization of undercooled melts. The treatment is within the limits of capillary theory. Two basic models are compared: (1) According to the first one (model A), the phase with lower energy of formation of critical nucleus is predominantly formed. In an enantiotropic-type phase diagram there is...
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Solidification needs an undercooling to drive the solidification front. If large undercoolings are achieved, metastable solid materials are solidified from the undercooled melt. Containerless processing provides the conditions to achieve large undercoolings since heterogeneous nucleation on container walls is completely avoided. In the present contribution both electromagnetic and electrostatic...
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ژورنال
عنوان ژورنال: Bulletin of the Japan Institute of Metals
سال: 1988
ISSN: 0021-4426,1884-5835
DOI: 10.2320/materia1962.27.32