Equiaxed dendritic growth in nearly isothermal conditions: A study combining in situ and real-time experiment with large-scale phase-field simulation
| Autor: | Yun Chen, Shanshan Li, Henri Nguyen-Thi, Liyuan Hou, Yanfei Cao, Xing-Qiu Chen, Dianzhong Li, Guillaume Reinhart, Tongzhao Gong |
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| Přispěvatelé: | Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research [Chinese Academy of Sciences] (IMR), Chinese Academy of Sciences [Beijing] (CAS)-Chinese Academy of Sciences [Beijing] (CAS), Baotou Research Institute on Rare Earths, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), GDR 2799 Micropesanteur Fondamentale & Appliquée |
| Rok vydání: | 2021 |
| Předmět: |
Convection
Equiaxed crystals equiaxed dendritic growth Materials science Cmax Thermodynamics 02 engineering and technology 010402 general chemistry 01 natural sciences Isothermal process [SPI.MAT]Engineering Sciences [physics]/Materials Cmin Phase (matter) Materials Chemistry General Materials Science Supercooling [PHYS]Physics [physics] Natural convection polycrystalline solidification large-scale simulation synchrotron X-ray radiography 021001 nanoscience & nanotechnology 0104 chemical sciences Mechanics of Materials phase-field method 0210 nano-technology |
| Zdroj: | Materials Today Communications Materials Today Communications, 2021, 28, pp.102467. ⟨10.1016/j.mtcomm.2021.102467⟩ |
| ISSN: | 2352-4928 |
| DOI: | 10.1016/j.mtcomm.2021.102467 |
| Popis: | International audience; The equiaxed dendritic growth of Al-Cu alloys in nearly isothermal temperature field under continuous cooling condition is studied using in situ and real-time observation of experiments by synchrotron X-ray radiography and large-scale quantitative two-dimensional (2D) phase-field (PF) simulations. It is revealed that the equiaxed dendritic morphology and the secondary dendritic arm spacing (SDAS) in the 2D PF simulations are in a reasonable agreement with the experimental data. Increasing the cooling rates results in a smaller SDAS, as predicted by the analytical Kattamis-Flemings model. The transformation kinetics of solid fraction can be described by the Johnson-Mehl-Avrami-Kologoromov (JMAK) theory, but quantitative differences between the experiments and 2D PF simulations are significant. The maximum solute concentration Cmax in liquid is approximately equal to the equilibrium concentration, which depends on the undercooling rather than the cooling rate. But the minimum solute concentration Cmin in solid decreases with the cooling rate, thus leading to a larger segregation ratio SR = Cmax/Cmin. Moreover, the liquid gravity-driven natural convection is considered in simulations. The liquid flow slightly increases the SDAS but has no apparent effect on solid fraction, and the segregation ratio is slightly reduced by the liquid convection, which could be attributed to the almost same Cmax and enlarged Cmin. |
| Databáze: | OpenAIRE |
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