TY - JOUR AU - Roósz, András AU - Rónaföldi, Arnold AU - Kissné Svéda, Mária AU - Veres, Zsolt TI - The Angular Velocity as a Function of the Radius in Molten Ga75In25 Alloy Stirred Using a Rotation Magnetic Field JF - METALS J2 - METALS-BASEL VL - 14 PY - 2024 IS - 3 PG - 20 SN - 2075-4701 DO - 10.3390/met14030368 UR - https://m2.mtmt.hu/api/publication/34751010 ID - 34751010 LA - English DB - MTMT ER - TY - BOOK ED - Roósz, Prof. András AU - Roósz, András AU - Li, Yuze AU - Al-Omari, Kassab AU - Rónaföldi, Arnold AU - Jenő, Kovács AU - Sycheva, Anna AU - Gerhard, Zimmermann AU - Kissné Svéda, Mária AU - Henri, Nguyen-Thi AU - N., Mangelinck-Noël AU - Veres, Zsolt TI - Effect of Microgravity and Magnetic Steering on the Melt Flow and the Microstructure of Solidified Alloys PB - B P International CY - Kolkata PY - 2024 SP - 279 SN - 9788196972318 DO - 10.9734/bpi/mono/978-81-969723-1-8 UR - https://m2.mtmt.hu/api/publication/34596998 ID - 34596998 LA - English DB - MTMT ER - TY - JOUR AU - Roósz, András AU - Rónaföldi, Arnold AU - Kissné Svéda, Mária AU - Veres, Zsolt TI - Comparison of Dynamical and Empirical Simulation Methods of Secondary Dendrite Arm Coarsening JF - CRYSTALS J2 - CRYSTALS VL - 12 PY - 2022 IS - 12 PG - 19 SN - 2073-4352 DO - 10.3390/cryst12121834 UR - https://m2.mtmt.hu/api/publication/33338961 ID - 33338961 LA - English DB - MTMT ER - TY - JOUR AU - Al-Omari, Kassab AU - Roósz, András AU - Rónaföldi, Arnold AU - Kissné Svéda, Mária AU - Veres, Zsolt TI - Macrosegregation Evolution in Eutectic Al-Si Alloy under the Influence of a Rotational Magnetic Field JF - METALS J2 - METALS-BASEL VL - 12 PY - 2022 PG - 17 SN - 2075-4701 DO - 10.3390/met12111990 UR - https://m2.mtmt.hu/api/publication/33259042 ID - 33259042 LA - English DB - MTMT ER - TY - JOUR AU - Roósz, András AU - Rónaföldi, Arnold AU - Kissné Svéda, Mária AU - Veres, Zsolt TI - Effect of crucible wall roughness on the laminar/turbulent flow transition of the Ga75In25 alloy stirred by a rotating magnetic field JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 12 PY - 2022 IS - 1 PG - 16 SN - 2045-2322 DO - 10.1038/s41598-022-21898-7 UR - https://m2.mtmt.hu/api/publication/33205870 ID - 33205870 AB - The critical magnetic induction (Bcr) values of a melt flow produced by a rotating magnetic field (RMF), remaining laminar or turbulent, are essential in different solidification processes. In an earlier paper (Metall Res Technol 100: 1043–1061, 2003), we showed that Bcr depends on the crucible radius (R) and frequency of the magnetic field (f). The effect of wall roughness (WR) on Bcr was investigated in this study. Using ten different wall materials, we determined the angular frequency (ω) and Reynolds number (Re) as a function of the magnetic induction (B) and f using two different measuring methods (pressure compensation method, PCM; height measuring method, HMM). The experiments were performed at room temperature; therefore, the Ga75wt%In25wt% alloy was chosen for the experiments. Based on the measured and calculated results, a simple relationship was determined between Bcr and Re*, f, R, and WR, where the constants K1, K2, K3, and K4 depended on the physical properties of the melt and wall material: LA - English DB - MTMT ER - TY - JOUR AU - Zhang, Haijie AU - Wu, Menghuai AU - Rodrigues, Christian M.G. AU - Ludwig, Andreas AU - Kharicha, Abdellah AU - Rónaföldi, Arnold AU - Roósz, András AU - Veres, Zsolt AU - Kissné Svéda, Mária TI - Dendrite fragmentation mechanism under forced convection condition by rotating magnetic field during unidirectional solidification of AlSi7 alloy JF - ACTA MATERIALIA J2 - ACTA MATER VL - 241 PY - 2022 PG - 14 SN - 1359-6454 DO - 10.1016/j.actamat.2022.118391 UR - https://m2.mtmt.hu/api/publication/33117826 ID - 33117826 AB - Forced convection and its effect on the microstructure evolution of an Al-7wt.%Si alloy during unidirectional solidification were studied experimentally. Under natural convection (gravity), columnar structures develop. However, under forced convection by activating a rotating magnetic field (RMF: 10 mT, 50 Hz), many equiaxed grains form in the half-radius region of the cylindrical sample, and a severe macrosegregation channel forms at the centre of the sample. Crystal fragmentation is regarded as the main source of equiaxed grains, but their formation mechanism and the fragment transport phenomenon are not fully understood. A mixed equiaxed-columnar solidification model with extension to consider two dendrite fragmentation mechanisms (capillary-driven and flow-driven), was used to reproduce the experiment with the objective to investigate the formation process of the microstructure and macrosegregation. Under the effect of the RMF-induced primary/secondary flow, the capillary-driven fragmentation mechanism, which is associated with dendrite coarsening, operates mainly in the peripheral region of the sample at a certain depth of the mushy zone. These fragments are difficult to be transported out of the (columnar dendritic) mushy zone. The flow-driven fragmentation mechanism associated with the interdendritic flow-induced re-melting of dendrites, operates mostly near the front of the mushy zone and/or around the central segregation channel. Some of these fragments can be transported out of the columnar tip region. In this case, a thin undercooled layer exists. Therefore, fragments can grow and become equiaxed grains. Some fragments are transported distally from the mushy zone into the bulk superheated region and are re-melted/destroyed there. The fragments, which continue to grow in the deep mushy zone or in the thin undercooled layer, are easily trapped by columnar dendrites, thereby competing with the growth of columnar dendrites to form a mixed columnar-equiaxed structure or even leading to a columnar-to-equiaxed transition. LA - English DB - MTMT ER - TY - JOUR AU - Roósz, András AU - Rónaföldi, Arnold AU - Yuze, Li AU - Nathalie, Mangelinck-Noel AU - Gerhard, Zimmermann Henri Nguyen-Thi AU - Kissné Svéda, Mária AU - Veres, Zsolt TI - Microstructure Analysis of Al-7 wt% Si Alloy Solidified on Earth Compared to Similar Experiments in Microgravity JF - CRYSTALS J2 - CRYSTALS VL - 12 PY - 2022 IS - 9 PG - 29 SN - 2073-4352 DO - 10.3390/cryst12091226 UR - https://m2.mtmt.hu/api/publication/33074217 ID - 33074217 LA - English DB - MTMT ER - TY - JOUR AU - Zhang, Haijie AU - Wu, Menghuai AU - Zhang, Zhao AU - Ludwig, Andreas AU - Kharicha, Abdellah AU - Rónaföldi, Arnold AU - Roósz, András AU - Veres, Zsolt AU - Kissné Svéda, Mária TI - Experimental Evaluation of MHD Modeling of EMS During Continuous Casting JF - METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE J2 - METALL MATER TRANS B VL - 53 PY - 2022 IS - 4 SP - 2166 EP - 2181 PG - 16 SN - 1073-5615 DO - 10.1007/s11663-022-02516-3 UR - https://m2.mtmt.hu/api/publication/32793546 ID - 32793546 AB - Electromagnetic stirring (EMS) has been recognized as a mature technique in steel industry to control the as-cast structure of steel continuous casting (CC), and computational magnetohydrodynamic (MHD) methods have been applied to study the EMS efficiency. Most MHD methods de-coupled the calculations of electromagnetic and flow fields or simplifications were made for the flow–electromagnetic interactions. However, the experimental validations of the MHD modeling have been rarely reported or very limited. In this study, we present a benchmark, i.e., a series of laboratory experiments, to evaluate the MHD methods, which have been typically applied for steel CC process. Specifically, a rotating magnetic field (RMF) with variable intensity and frequency is considered. First experiment is performed to measure the distribution of magnetic field without any loaded sample (casting); the second experiment is conducted to measure the RMF-induced torque on a cylindrical sample (different metals/alloys in solid state); the third experiment is (based on a special device) to measure the RMF-induced rotational velocity of the liquid metal (Ga75In25), which is enclosed in a cylindrical crucible. The MHD calculation is performed by coupling ANSYS Maxwell and ANSYS Fluent. The Lorentz force, as calculated by analytical equations, ANSYS Fluent addon MHD module, and external electromagnetic solver, is added as the source term in Navier–Stokes equation. By comparing the simulation results with the benchmark experiments, the calculation accuracy with different coupling methods and modification strategies is evaluated. Based on this, a necessary simplification strategy of the MHD method for CC is established, and application of the simplified MHD method to a CC process is demonstrated. LA - English DB - MTMT ER - TY - JOUR AU - Rónaföldi, Arnold AU - Veres, Zsolt AU - Kissné Svéda, Mária AU - Roósz, András TI - New Equipment and Method for Refining the Solidified Grain Structure JF - METALS J2 - METALS-BASEL VL - 12 PY - 2022 IS - 4 PG - 18 SN - 2075-4701 DO - 10.3390/met12040658 UR - https://m2.mtmt.hu/api/publication/32781495 ID - 32781495 LA - English DB - MTMT ER - TY - JOUR AU - Roósz, András AU - Rónaföldi, Arnold AU - Yuze, L AU - Nathalie, Mangelinck-Noël AU - Gerhard, Zimmermann AU - Henri, Nguyen-Thi AU - Kissné Svéda, Mária AU - Veres, Zsolt TI - Influence of Solidification Parameters on the Amount of Eutectic and Secondary Arm Spacing of Al–7wt% Si Alloy Solidified under Microgravity JF - CRYSTALS J2 - CRYSTALS VL - 12 PY - 2022 IS - 3 PG - 18 SN - 2073-4352 DO - 10.3390/cryst12030414 UR - https://m2.mtmt.hu/api/publication/32744577 ID - 32744577 LA - English DB - MTMT ER -