Modeling the heterogeneous nucleation in a melt modified with spherical nanoparticles
V.N. Popov
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Keywords: numerical simulation, modification, spherical nanoparticles, heterogeneous nucleation, crystallization, aluminum alloy
Abstract
The paper considers a model of nucleation of crystal phase during cooling of a modified melt below the liquidus point. We demonstrated a connection between the overcooling factor, nucleus size forming at the particle surface, and the amount of consumed energy. Numerical simulation was performed for solidification of a modified bicomponent aluminum melt in a cylindrical crucible with account for thermodynamics, heterogeneous nucleation and crystallization. We found the conditions of crystal nuclei formations: both for the cases with the size higher or smaller that the size of seeds. It was shown that efficient modification of the metal needs the use of powders with maximally homogeneous size. The reliability of this model is confirmed by reasonable compliance between the simulation and physical experimental data.
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