Non-Equilibrium Solidification of Undercooled Metallic 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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Phase-field modeling of rapid alloy solidification, in which the rejection of latent heat from the growing solid cannot be ignored, has lagged significantly behind the modeling of conventional casting practices which can be approximated as isothermal. This is in large part due to the fact that if realistic materials properties are adopted, the ratio of the thermal to solute diffusivity (the Lew...
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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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ژورنال
عنوان ژورنال: Key Engineering Materials
سال: 1993
ISSN: 1662-9795
DOI: 10.4028/www.scientific.net/kem.81-83.83