Molecular dynamics simulation of athermal heterogeneous nucleation of solidification
T Fujinaga and Y Shibuta, COMPUTATIONAL MATERIALS SCIENCE, 164, 74-81 (2019).
Athermal heterogeneous nucleation via grain refiners inoculated in undercooled Al melt is investigated by molecular dynamics (MD) simulations. A thin solid Al layer appears on close-packed surfaces of a cubic Ti particle and it grows to a spherical cap consisting of face- centered-cubic (FCC) Al, whereas no cap structure appears on the other surfaces. There is a threshold undercooling temperature dividing growth modes between stagnation and free growth. Since threshold undercooling temperature is proportional to the inverse of effective particle radius, cap formation at the surface of the Ti particle is regarded as athermal heterogeneous nucleation. Additional calculation of a solid growth of undercooled melt Al on the flat Ti surface reveals that initial solid formation on the Ti surface is caused by adsorption rather than classical (i.e., thermally-activated) heterogeneous nucleation. It is significant in this study to shed light on the mechanism of athermal heterogeneous nucleation from atomistic viewpoint since there is no atomistic description in an existing theoretical model of free growth.
Return to Publications page