Effect of a transverse magnetic field on solidification structure in directionally solidified Sn–Pb hypoeutectic alloys

• Published in: Journal of crystal growth Vol. 402; pp. 319 - 324
• Main Authors: Du, Dafan, Lu, Zhenyuan, Gagnoud, Annie, Fautrelle, Yves, Ren, Zhongming, Lu, Xionggang, Moreau, Rene, Li, Xi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.09.2014; Elsevier
• Subjects: A1. Directional solidification; A1. Transverse magnetic field; A2. Dendrite spacing; Alloys; B1. Segregation; B1. Sn–Pb alloys; Chemical Sciences; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Dendritic structure; Directional solidification; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Growth from melts; zone melting and refining; Liquids; Magnetic fields; Material chemistry; Materials science; Methods of crystal growth; physics of crystal growth; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Solidification; Solubility, segregation, and mixing; phase separation; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Thermoelectricity; Tin base alloys; A1. Transverse magnetic field; A1. Directional solidification; B1. Segregation; B1. Sn–Pb alloys; A2. Dendrite spacing; Liquid solid interface; Directional solidification; Segregation; B1. Sn-Pb alloys; Solidification front; Thermoelectric materials; Morphology; Growth mechanism; Dendrites; Crystal growth from melts
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2014.06.031

Effect of a transverse magnetic field on the macrosegregation and the growth of the Sn dendrite in the directionally solidified Sn–Pb alloys was investigated experimentally. The results indicated that the magnetic field modified the shape of the liquid/solid interface and the dendrite morphology significantly. Indeed, the application of the magnetic field caused the formation of the sloping interface and the refinement of the dendrite. It is also found that the magnetic field decreased the mushy zone length. These effects were enhanced with the increase of the magnetic field intensity and the decrease of the growth speed. Further, the Seebeck thermoelectric force (ES) at the liquid/solid interface in the Sn-20wt%Pb alloy was measured in-situ and the results indicated that the value of the Seebeck thermoelectric force was about 1µV. The modification of the solidification structure during directional solidification under the magnetic field may be attributed to the interdendritic thermoelectric magnetic convection (TEMC). •The transverse magnetic field modified the shape of the solid–liquid interfaces.•The magnetic field decreased the mushy zone length and the dendrite spacing.•The Seebeck thermoelectric force at the interface was measured in-situ.•The above results may be attributed to the TEMC in the mushy zone.