Crystallization of aluminum droplet at low supercooling: theoretical analysis by homogeneous nucleation model

0561156 - FZÚ 2023 RIV SK eng A - Abstract
Kožíšek, Zdeněk - Král, Robert - Zemenová, Petra
Crystallization of aluminum droplet at low supercooling: theoretical analysis by homogeneous nucleation model.
Book of Abstracts of the 31st Joint Seminar Development of Materials Science in Research and Education (DMSRE). Bratislava: FCHPT STU, 2022 - (Koman, M.; Behúlová, M.; Kožíšek, Z.). s. 27-27. ISBN 978-80-8208-086-8. ISSN 1757-8981.
[DMSRE seminar: Development of Materials Science in Research and Education (DMSRE) /31./. 05.09.2022-09.09.2022, Nová Lesná]
R&D Projects: GA MŠMT(CZ) EF16_019/0000760
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institutional support: RVO:68378271
Keywords : thermal analysis * nucleation * growth from melts * modeling
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)

Crystallization in an undercooled Aluminum (Al) droplet occurs via the formation of crystalline nuclei by homogeneous or heterogeneous nucleation and successive growth of nuclei. Crystallization event at low undercooling 6.4 oC of 9.91 mg of a compact Al sample was detected using isothermal differential scanning calorimetry (DSC) after several tenths of minutes. Standard analysis based on Johnson-Mehl-Avram-Kolmogorov (JMAK) model is not appropriate in this case as Avrami parameter n, which is closely connected to the dimensionality of the system, is too low to fit the crystallization data via JMAK model. Al growth rate is extremely high and that is why we presume that the time delay of crystallization, detected by DSC, is slightly higher than nucleation time delay. A homogeneous nucleation model is applied to determine the basic characteristics of nucleation: the size distribution of nuclei, nucleation rate, total number of nuclei and crystallization fraction at the nucleation process. The number of atoms in a liquid Aluminum droplet decreases with time as the formation of a new crystalline phase occurs. As a consequence, a decrease in stationary nucleation occurs.

Permanent Link: https://hdl.handle.net/11104/0333840