The prediction of structure evolution in Al-Si
                                 using phase field modeling method


               M. Mazalová^ 1,a, Y. Countinho^ 2, S. Chatterjee^ 2 and N. Moelans^ 2

^1 Department of Chemistry, Faculty of Science, Masaryk University,

Kotlářská 2, 611 37 Brno, Czech Republic

^2 Department of Metallurgy and Materials Engineering, KU Leuven,
Kasteelpark Arenberg 44, B-3001 Leuven, Belgium


                                      ^a 394206@mail.muni.cz


We present a theoretical study on the prediction of the structure evolution in system Al-Si. The
calculations were performed using the phase field modelling method and the Moose software [1]. The
applied Kim-Kim-Suzuki (KKS) model is a two-phase model (with a single order parameter η) with the
added complexity, which is done by introducing phase‑concentrations to both phases [2]. The
complementary calculations were performed using Thermo‑Calc software [3].

The construction of the model plays a crucial role in the studying of the structure evolution by
the phase field modelling method. Here, tree models for different temperatures were built. The
initial structure was read from the SEM images provided by Kim Vanmeensel group. The composition,
mobility and the description of the free energy evolution with respect to the temperature and
composition were determined using the Al-Mg COST 507 thermochemical database for light metal alloys
[4].

The number, volume and shape of the precipitates was observed with respect to the changing
temperature and time of the evolution. The initial structure consisted mainly of the matrix fcc
aluminium phase. During the evolution, the small precipitates with diamond structure (consisting
mainly of silicon) were growing and forming spherical shapes. The theoretical results were compared
with the experimental ones provided by the group of Kim Vanmeensel.



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https://doi.org/10.1016/j.anucene.2014.09.060.

[2]   Kim et al., Phys. Rev. E, 60 (1999) 7186-7197.

[3]   Andersson J.O., Helander T., Höglund L., Shi P.F., Sundman B., Calphad, 26 (2002) 273-312.

[4]   Ansara I., Dinsdale A.T., Rand M.H., ed.: COST 507. Definition of Thermophysical Properties
to Provide a Database for the Development of New Light Alloys. Thermochemical Database for Light
Metal Alloys. Vol. 2., Scientific Group Thermodata Europe Database, EUR 18499 en (1998).