volume | PIER Journals

Abstract

The nucleation and growth of primary Al₂Cu phase in the Al-34.3wt%Cu hypereutectic alloy without and with a 12 T magnetic fields have been investigated by differential thermal analysis (DTA). The DTA curves indicated that the nucleation temperature of primary phase was significantly reduced in a magnetic field. The X-ray diffraction (XRD) patterns confirmed that the c-axes of primary Al₂Cu crystals oriented along the direction parallel to a magnetic field. The microstructures showed that primary crystals aligned along a magnetic field and that their number distinctly increased with increasing a magnetic field as well. The suppression of nucleation in a magnetic could be caused by the increase of the interfacial energy between the liquid and nucleus and the reduction of atom diffusion rates while the orientation of primary crystals were mainly attributed to both of the magnetic toque and the thermoelectric magnetohydrodynamic (TEMHD) flows.

1. Goetz, A., "On mechanical and magnetic factors influencing the orientation and perfection of bismuth single-crystals," Physical Review, Vol. 35, 193-207, 1930.
doi:10.1103/PhysRev.35.193 Google Scholar

2. Mikelson, A. E. and Y. K. Karklin, "Control of crystallization processes by magnetic fields," Journal of Crystal Growth, Vol. 52, 524-529, 1981.
doi:10.1016/0022-0248(81)90333-X Google Scholar

3. Savitsky, E. M., R. S. Torchinova, and S. A. Turanov, "Effect of crystallization in magnetic field on the structure and magnetic properties of Bi-Mn alloys," Journal of Crystal Growth, Vol. 52, 519-523, 1981.
doi:10.1016/0022-0248(81)90332-8 Google Scholar

4. De Rango, P., M. Lees, P. Lejay, A. Sulpice, R. Tournier, M. Ingold, P. Germi, and M. Pernet, "Texturing of magneticmaterials at high temperature by solidification in a magnetic field," Nature, Vol. 349, 770-772, 1991.
doi:10.1038/349770a0 Google Scholar

5. Liu, H. B., P. J. Ferreira, and J. B. Vander Sande, "Processing bi-2212/ag thick films under a high magnetic field: On the bi-2212/ag interface effect," Physica C: Superconductivity, Vol. 303, 161-168, 1998.
doi:10.1016/S0921-4534(98)00250-0 Google Scholar

6. Gaucherand, F. and E. Beaugnon, "Magnetic texturing in ferromagnetic cobalt alloys," Physica B, Vol. 346-347, 262-266, 2004.
doi:10.1016/j.physb.2004.01.062 Google Scholar

7. Lee, K. H., J. M. Cho, and W. Sigmund, "Control of growth orientation for carbon nanotubes," Applied Physical Letters, Vol. 82, 448-450, 2003.
doi:10.1063/1.1535269 Google Scholar

8. Torbet, J., J. M. Freyssinet, and G. Hudry-Clergeon, "Oriented fibrin gels formed by polymerization in strong magnetic fields," Nature, Vol. 289, 91-93, 1981.
doi:10.1038/289091a0 Google Scholar

9. Tournier, R. F. and E. Beaugnon, "Texturing by cooling a metallic melt in a magnetic field," Science and Technology of Advanced Materials, Vol. 10, 014501, 2009.
doi:10.1088/1468-6996/10/1/014501 Google Scholar

10. Tournier, R. F, "Presence of intrinsic growth nuclei in overheated and undercooled liquid elements," Physica B, Vol. 392, 79-91, 2007.
doi:10.1016/j.physb.2006.11.002 Google Scholar

11. Li, C. J., Z. M. Ren, K. Deng, G. H. Cao, Y. B. Zhong, and Y. Q. Wu, "Design and application of differential thermal analysis apparatus in high magnetic fields," Review of Scientific Instruments, Vol. 80, 073907, 2009.
doi:10.1063/1.3186058 Google Scholar

12. Porter, D. A. and K. E. Easterling, Phase Transformations in Metals and Alloys, 2 Ed., Chapman & Hall, London, 1992.

13. Magomedov, M. N., "On the magnetic-field-induced changes in the parameters of phase transitions," Technical Physics Letters, Vol. 28, 116-118, 2002.
doi:10.1134/1.1458508 Google Scholar

14. Turnbull, D., "Formation of crystal nuclei in liquid metals," Journal of Applied Physics, Vol. 21, 1022-1028, 1950.
doi:10.1063/1.1699435 Google Scholar

15. Fujimura, Y. and M. Lino, "The surface tension of water under high magnetic fields," Journal of Applied Physics, Vol. 103, 124903-4, 2008.
doi:10.1063/1.2940128 Google Scholar

16. Li, C. J., H. Yang, Z. M. Ren, W. L. Ren, and Y. Q. Wu, "On nucleation temperature of pure aluminum in magnetic fields," Progress In Electromagnetics Research Letters, Vol. 15, 45-52, 2010.
doi:10.2528/PIERL10041412 Google Scholar

17. Spaepen, F., "Interfaces and stresses in thin films," Acta Materialia, Vol. 48, 31-42, 2000.
doi:10.1016/S1359-6454(99)00286-4 Google Scholar

18. Turnbull, D. and J. C. Fisher, "Rate of nucleation in condensed systems," Journal of Chemical Physics, Vol. 17, 71-73, 1949.
doi:10.1063/1.1747055 Google Scholar

19. Botton, V., P. Lehmann, R. Bolcato, R. Moreau, and R. Haettel, "Measurement of solute diffusivities. Part II. Experimental measurements in a convection-controlled shear cell. Interest of a uniform magnetic field," International Journal of Heat and Mass Transfer, Vol. 44, 3345-3357, 2001.
doi:10.1016/S0017-9310(00)00362-8 Google Scholar

20. Miyake, T., Y. Inatomi, and K. Kuribayashi, "Measurement of diffusion coefficient in liquid metal under static magnetic field," Japan Journal of Applied Physics, Vol. 41, L811-L813, 2002.
doi:10.1143/JJAP.41.L811 Google Scholar

21. Youdelis, W. V., D. R. Colton, and J. Cahoon, "On the theory of diffusion in a magnetic field," Canadian Journal of Physics, Vol. 42, No. 11, 2238-2258, 1964.
doi:10.1139/p64-205 Google Scholar

22. Ferreira, P. J., H. B. Liu, and J. B. Vander Sande, "A model for the texture development of high-Tc surperconductors under an elevated magnetic field," Journal of Materials Research, Vol. 14, 2751-2763, 1999.
doi:10.1557/JMR.1999.0368 Google Scholar

23. Asai, S., K. Sassa, and M. Tahashi, "Crystal orientation of non-magnetic materials by imposition of a high magnetic field," Science and Technology of Advanced Materials, Vol. 4, 455-460, 2003.
doi:10.1016/j.stam.2003.07.001 Google Scholar

24. Sugiyama, T., M. Tahashi, K. Sassa, and S. Asai, "The control of crystal orientation in non-magnetic metals by imposition of a magnetic field," ISIJ International, Vol. 43, 855-861, 2003.
doi:10.2355/isijinternational.43.855 Google Scholar

25. Nakagawa, Y., "An experiment on the inhibition of thermal convection by a magnetic field," Nature, Vol. 175, 417-419, 1955.
doi:10.1038/175417b0 Google Scholar

26. Oreper, G. M. and J. Szekely, "The effect of an externally imposed magnetic field on buoyancy driven flow in a rectangular cavity," Journal of Crystal Growth, Vol. 64, 505-515, 1983.
doi:10.1016/0022-0248(83)90335-4 Google Scholar

27. Lehmann, P., R. Moreau, D. Camel, and R. Bolcato, "Modification of interdendritic convection in directional solidification by a uniform magnetic field," Acta Materialia, Vol. 46, 4067-4079, 1998.
doi:10.1016/S1359-6454(98)00064-0 Google Scholar

28. Moreau, R., O. Laskar, M. Tanaka, and D. Camel, "Thermoelectric magnetohydrodynamic effects on solidification of metallic alloys in the dendritic regime," Materials Science and Engineering A, Vol. 173, 93-100, 1993.
doi:10.1016/0921-5093(93)90194-J Google Scholar

29. Gorbunov, L. A., "Effect of thermoelectromagnetic convection on the production of bulk single crystals consisting of semiconductor melts in a constant magnetic field," Magnetohydrodynamics, Vol. 23, 404-408, 1988. Google Scholar

30. Li, X., Y. Fautrelle, and Z. M. Ren, "Influence of thermoelectric effects on the solid-liquid interface shape and cellular morphology in the mushy zone during the directional solidification of Al-Cu alloys under a magnetic field," Acta Materialia, Vol. 55, 3803-3813, 2007.
doi:10.1016/j.actamat.2007.02.031 Google Scholar

31. Shercliff, J. A., "Thermoelectric magnetohydrodynamics," Journal of Fluid Mechanics, Vol. 91, 231-251, 1979.
doi:10.1017/S0022112079000136 Google Scholar

32. Bretonnet, J. L., J. Auchet, and J. G. Gasser, "Electrical transport properties of the liquid Al-Cu alloys," Journal of Non-Crystalline Solids, Vol. 117-118, 395-398, 1990.
doi:10.1016/0022-3093(90)90961-K Google Scholar

Dr. Chuanjun Li

Dr. Zhongming Ren

Dr. Weili Ren

Dr. Yuqin Wu

Dr. Yunbo Zhong

Dr. Kang Deng