Visualisation of the Melt Flow under Rotating Magnetic Field

et al. 2014

MSF

Self Cite

Abstract. The peritectic alloys, such as some types of steel, Ni-Al, Fe-Ni, Ti-Al, Cu-Sn, are commercially important. In contrast to other types of alloys, many unique structures (e.g. banded or island ones) can form when peritectic alloys are directionally solidified under various solidification conditions. It can be observed in the course of the directional solidification experiments performed in a rotating magnetic field (RMF) that the melt flow has a significant effect on the solidified structure of Sn-Cd alloys. This effect was investigated experimentally for the case of Sn-1.6 wt% Cd peritectic alloy. For this purpose, a Bridgman-type gradient furnace was equipped with an inductor, which generates a rotating magnetic field in order to induce a flow in the melt. As a result, the forced melt flow substantially changes the solidified cellular microstructure. The cell size and the volume fraction of the primary tin phase were measured by an image analyzer on the longitudinal polished sections along the entire length of the samples. The microstructure was investigated by scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS).

Section: Resultssupporting

confidence: 61%

Section: Macrosegregationmentioning

confidence: 60%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The Effect of Rotating Magnetic Field on the Solidified Structure of Sn-Cd Peritectic Alloys

Svéda

Sycheva

et al. 2014

MSF

Self Cite

“…The magnetic field was generated by the 3-phase and 2-pole inductor placed around the 4-zone tube furnace. The detailed description of the experimental facility can be found in [8,9]. The magnetic field was switched off before starting the solidification in order to let the first part of a sample solidify without flow.…”

Section: Materials and Experimentsmentioning

confidence: 99%

Unidirectional solidification of Sn- Pb alloys under forced melt flow

IOP Conf. Ser.: Mater. Sci. Eng.

Rogozsán

Rónaföldi

et al. 2012

On the relation between primary and eutectic solidification structures in gray iron L Elmquist and P A Sonawane -Modeling of primary dendrite arm spacing variations in thin-slab casting of low carbon and low alloy steels H Mehrara, B Santillana, D G Eskin et al. Abstract. Cylindrical Sn-Pb alloy samples of different compositions (10, 20 and 30 wt.-% Pb) were prepared from high purity (4N) components. After metals have been melted, a rotating magnetic field (RMF) with an induction of 150 mT and a frequency of 50 Hz was switched on in order to homogenize the liquid. The electromagnetic field was generated by a 3-phase, 2-pole inductor. Just before the start of the solidification process, the magnetic field was switched off to achieve a microstructure free of melt flow influence. The sample translation velocity was constant (0.05 mm/s), and the temperature gradient changed from 7 to 3 K/mm during the solidification process. The first half part of each sample solidified without influence of rotating magnetic field while solidification of the second half part proceeded under the action of the RMF. The columnar microstructure formed in the absence of RMF induced fluid flow was replaced after switching on the RMF by a characteristic "Christmas tree"-like macrosegregated structure with equiaxed dendrites. The secondary dendrite arm spacing and the volume fraction of primary tin phase (dendrite) were measured by an automatic image analyzer on the longitudinal polished sections along the whole length of the samples. The effect of the forced melt flow and alloy composition on its micro-and macrostructure development was investigated.

Effect of the High Rotating Magnetic Field (min. 30 mT) on the Unidirectionally Solidified Structure of Al7Si0.6Mg Alloy

Rónaföldi

Roósz

2010

MSF

The topic of this paper is the unidirectional solidification of ternary Al7Si0.6Mg aluminium alloy in a rotating magnetic field of 30 -150 mT and the characterisation of effect of stirring on the solidified structure. During performing the experiment-series, one of the three solidification parameters (temperature gradient, solid/liquid interface velocity and magnetic induction) was continuously changed and the other two of them was kept on a constant value. The effect of these parameters on the developed structures was analysed during the evaluation of the experimental results. Moreover, the extent of Si-macrosegregation as well as the change of the secondary dendrite arm spacing were investigated on the longitudinal and cross-sections of samples as a function of the three basic parameters.