Effect of the rotating magnetic field on the unidirectionally solidified macrostructure of Al6Si4Cu alloy

et al. 2013

MSF

Al–7wt.-% Si–1wt.-% Fe alloy was solidified unidirectionally in the Crystallizer with High Rotating Magnetic Field (CHRMF). The diameter of sample was 8 mm and its length was 120 mm. The parameters of solidification were as follows: solid/liquid interface velocity ~0.082 mm/s, temperature gradient 7+/-1 K/mm, magnetic induction 0 and 150 mT, frequency of magnetic field 0 and 50 Hz. The structure solidified without rotating magnetic field (RMF) showed a homogeneous, columnar dendritic one. The structure solidified by using magnetic stirring showed a dual periodicity. On the one hand, the branches of the “Christmas tree”-like structure known from the earlier experiments contained Al+Si binary eutectic. On the other hand, bands with higher Fe- and Si-content formed in the sample, which were at a larger distance from each other than the branches of the “Christmas tree” structure. The developed microstructure was analyzed by SEM with EDS. The average Si- and Fe-concentrations were measured on the longitudinal section at given places along the length of sample. Furthermore the Si- and the Fe-concentrations close to the bands and among the bands as well as the composition of the compound phases were determined.

Section: Evaluation Of Experimentssupporting

confidence: 73%

Effect of High Rotating Magnetic Field on the Solidified Structure of Al–7wt.%Si–1wt.%Fe Alloy

et al. 2013

MSF

“…In the different Al-alloy samples solidified by using this facility a "Christmas tree"-like macrostructure was formed. The macrostructure of these samples [5,6,7,8] differs significantly from the macrostructure published earlier [9,10].…”

Section: The Application Of Measuring Results In the Practicecontrasting

confidence: 54%

Effect of Crucible Diameter and Wall Roughness on the Melt Flow Generated by Rotating Magnetic Field

2010

MSF

“…2b) because of starting the melt flow. The homogenous concentration-distribution changed under the influence of melt flow and a characteristic "Christmas tree"-like microstructure developed [5,6].…”

Section: Qualitative Description Of the Solidified Structurementioning

confidence: 99%

Unidirectional Solidification of Pb-Sn Alloys in a Rotating Magnetic Field

2014

MSF

Cylindrical Pb-Sn alloy samples (diameter: 8 mm, length: 120 mm) of different compositions (30, 40 and 50 wt.% of Sn) were prepared from high pure (4N) components. The unidirectional solidification experiments have been performed according to the upward vertical Bridgman-method by using a rotating magnetic field (RMF) with a magnetic induction of 150 mT and with a frequency of 50 Hz. The sample-movement 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 of samples was solidified without using the magnetic field and the second half was solidified by using the magnetic field. Under the influence of this strong flow induced by the magnetic field, the columnar microstructure of the first part decomposed and a characteristic "Christmas tree"- like macrosegregated structure with equiaxed Pb-dendrites was developed. The secondary dendrite arm spacing (SDAS) and the volume percent of primary Pb-phase (dendrite) were measured by an automatic image analyser on the longitudinal polished sections along the whole length of the samples. The effect of the forced melt flow on the micro-and macrostructure was studied in case of the different sample compositions.