Influences of travelling magnetic field on the dendritic structures of Sna1.8Cd peritectic alloy during directional solidification

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2013-08, Vol.112 (2), p.363-370
• Main Authors: Wang, Lei, Shen, Jun, Yin, Xiao, Du, Yujun, Xiong, Yilong, Fu, Hengzhi
• Format: Article
• Language: English
• Subjects: Cadmium base alloys; Dendritic structure; Directional solidification; Magnetic fields; Mathematical models; Melts; Peritectic alloys; Solidification
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-013-7672-9

The effects of melt flow driven by a travelling magnetic field (TMF) on solidification structures of Sna1.8 wt.% Cd peritectic alloy have been investigated numerically and experimentally. Numerical results indicate that the flow velocity at the solid-liquid interface under a downward TMF is smaller than that under an upward TMF. The experimental results show that the growth directions of dendrites are chaotic, and several crotches among the dendrites are observed at the solid-liquid interface in the case of no field. It is concluded from TMF results that the ordered growth of dendrites at two different directions occurs, and only one crotch among the dendrites appears at the solid-liquid interface. The location of the crotch gradually approaches the interface center with increasing magnetic field intensity (B?10.3 mT). Moreover, the growth of high-order branches occurs at the crotch under a downward TMF. A simple model is established for explanation and it well corresponds to the experimental results.