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Journal of Physical Studies 28(1), Article 1601 [7 pages] (2024)
DOI: https://doi.org/10.30970/jps.28.1601 SIMULATIONS OF THE SURFACE STRUCTURE OF MATERIALS AT THE BOUNDARY OF TWO PHASES
I. Shtablavyi
Ivan Franko National University of Lviv,
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The atomic structure at the boundary of two phases (liquid-gas, liquid-crystal) is an important factor that affects the course of physical processes associated with the sintering of powder materials by both classical methods and the use of additive technologies. In this regard, the atomic structure of surface thin layers at the liquid-gas and liquid-crystal interfaces for densely packed metals (Al, Cu) and silicon, which are usually the main components of light structural materials, is studied in this work. The computer simulation method was used to obtain the atomic configurations of the studied materials. Structure analysis was carried out using two-dimensional and three-dimensional pair correlation functions, as well as distributions of coordination numbers and relative free volume. As a result of the work, the main regularities of the formation of the surface atomic structure of materials depending on the temperature around the melting point were established. In particular, it is shown that for the case of all studied materials, the melting process begins within three or four surface atomic layers. Studies of the free volume of the surface of materials depending on the distance to the interface indicate a significant amount of it at the liquid-gas interface. This feature obviously contributes to the intensification of surface diffusion, which becomes more important in the case of two-component and multi-component systems. The temperature dependence of the coordination numbers depending on the distance to the surface, as well as the analysis of interatomic distances, indicate a decrease in the degree of ordering of atoms with distance from the silicon surface.
Key words: additive technologies, surface melting, short-range order structure, pair correlation functions.
