Crystal Alignment of Bi–Sn Alloy by Simultaneous Imposition of a Static Magnetic Field and an Alternating Current during Solidification

Abstract

Crystal alignment of a Bi-10mass%Sn alloy solidified under different electromagnetic field imposing condition has been experimentally investigated in this study. Simultaneous imposition of a static magnetic field and an alternating current excited an electromagnetic vibration and it promoted nucleation, and resulted in decrease of undercooling, though imposition of the static magnetic field alone did not affect the undercooling. Furthermore, grain size of the solidified structure under the simultaneous imposition of the static magnetic field and the alternating current was smaller than that solidified with the magnetic field alone or solidified without the electromagnetic field imposition. XRD pattern of the sample solidified without the electromagnetic field imposition was similar to that of bismuth powder. On the contrary, only specific crystal plane peaks were observed when the electromagnetic field was imposed on the sample during the solidification. That is, crystal alignment of bismuth rich primary phase was achieved not only by the static magnetic field imposition alone but also the simultaneous imposition of the static magnetic field and the alternating current. However, degree of the crystal alignment solidified under the latter electromagnetic condition was slightly higher than that solidified under the former electromagnetic condition.

Visualization Study on the Droplet Evolution Behaviors in Electroslag Remelting Process by Superimposing a Transverse Static Magnetic Field

“…When no external magnetic field was applied during the ESR process, the Lorentz force generated by the induced magnetic field and the remelting current was very small, and it could be ignored in our experiments due to the small remelting current. While a large external TSMF was superimposed with the AC current, a forceful electromagnetic vibration (EMV) [26][27][28][29] would be generated. The EMV is the Lorentz force (F = J × B, where J is the current density and B is the magnetic field intensity), whose amplitude and orientation is periodic changed corresponding with the time behavior of the AC current.…”

Thermoelectric properties of crystal aligned higher manganese silicide fabricated by solidification under magnetic field

“…6) On the other hand, solidification under a magnetic field has also been reported to directly yield crystal aligned structures in various alloys. [20][21][22][23][24][25][26][27][28][29][30][31][32] Iwai and Usui 20) showed that the c-axis of the Bi-rich primary phase in Bi-10 mass % Sn alloys can be aligned by simply applying a 8 T magnetic field during solidification. Legrand et al 21) succeeded in forming highly c-axis aligned Sm-Co alloys by applying a 2.5 T magnetic field during rapid solidification.…”