Effects of Electromagnetic Agitation on Crystal Growth during the Pure Aluminum Slow Cooling Process

Abstract:

Refining grains are important to obtain sound cast billets suitable for further processing. The structure refinement of low frequency electromagnetic field (LFEF) during the aluminum alloy semi-continuous casting process has been confirmed by many researchers. In this work, effects of the electromagnetic agitation on the crystal growth were investigated during the pure aluminum slow cooling process. The results showed that the grain refinement effect by electromagnetic agitation mainly occurred at the first half period of crystal growth. With increasing of applying LFEF treated time, the fine grain occupied the whole section of ingot, and the ratio of fine grain zone to the whole section was proportional to the treated time.

• Periodical: Materials Science Forum (Volume 993)
• Pages: 398-403
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.993.398
• Online since: May 2020
• Authors: Xiang Jie Wang*, Fang Yu, Peng Wei Li, Wei Sun, Hong Juan Tan, Lei Li, Jian Zhong Cui
• Keywords: Crystal Growth, Low Frequency Electromagnetic Field, Pure Aluminum, Refining Mechanism

References

[1] P. Schumacher, A. L. Greer, J. Worth, P. V. Evans, M. A. Kearns, P. Fisher, and A. H. Green, New studies of nucleation mechanisms in aluminium alloys: implications for grain refinement practice, Mater. Sci. Technol. 14 (1998) 394-404.

DOI: 10.1179/mst.1998.14.5.394

[2] D. H. StJohn, M. A. Easton, P. Cao, M. Bermingham and M. Qian, A Brief History of the Grain Refinement of Cast Light Alloys, Mater. Sci. Forum. 765 (2013) 123-129.

DOI: 10.4028/www.scientific.net/msf.765.123

[3] M. A. Easton and D. H. StJohn, Grain refinement of aluminum alloys: Part I. the nucleant and solute paradigms—a review of the literature, Metall. Trans. A. 30 (1999) 1613-1623.

DOI: 10.1007/s11661-999-0098-5

[4] C. Vives and R. Ricou, Experimental study of continuous electromagnetic casting of aluminum alloys, Metall. Trans. B. 16 (1985) 377-384.

DOI: 10.1007/bf02679730

[5] J. L. Meyer, N. El-Kaddah, J. Szekely, C. Vives and R. Ricou, A comprehensive study of the induced current, the electromagnetic force field, and the velocity field in a complex electromagnetically driven flow system, Metall. Trans. B. 18 (1987) 529-538.

DOI: 10.1007/bf02654265

[6] Z. V. Getselev, Casting in an electromagnetic field, J. Met. 23(1971) 38-43.

[7] C. Vives, Electromagnetic refining of aluminum alloys by the CREM process: Part I. Working principle and metallurgical results, Metall. Trans. B. 20 (1989) 623-629.

DOI: 10.1007/bf02655919

[8] C. Vives, Electromagnetic refining of aluminum alloys by the CREM process: Part II. Specific practical problems and their solutions, Metall. Trans. B. 20 (1989) 631-643.

DOI: 10.1007/bf02655920

[9] B. J. Zhang, G. M. Lu and J. Z. Cui, Effect of Electromagnetic Frequency on Microstructures of Continuous Casting Aluminum Alloys, Mater. Sci. Technol. 18 (2002) 401-403.

[10] B. J. Zhang, J. Z. Cui and G. M. Lu, Effect of low-frequency magnetic field on macrosegregation of continuous casting aluminum alloys, Mater. Lett. 57 (2003) 1707-1711.

DOI: 10.1016/s0167-577x(02)01055-8

[11] B. J. Zhang, J. Z. Cui and G. M. Lu, Effects of low-frequency electromagnetic field on microstructures and macrosegregation of continuous casting 7075 aluminum alloy, Mater. Sci. Eng. A. 355 (2003) 325-330.

DOI: 10.1016/s0921-5093(03)00105-9

[12] J. Dong and J. Z. Cui, Effect of low-frequency electromagnetic casting on the castability, microstructure, and tensile properties of direct-chill cast Al-Zn-Mg-Cu alloy, Metall. Mater. Trans. A. 35 (2004) 2487-2494.

DOI: 10.1007/s11661-006-0228-2

[13] Z. H. Zhao, J. Z. Cui, Dong J, Z. F. Wang and B. J. Zhang, Effect of low-frequency magnetic field on microstructures of horizontal direct chill casting 2024 aluminum alloy, J. Alloys. Compd. 396 (2005) 164-168.

DOI: 10.1016/j.jallcom.2004.12.020

[14] Y. B. Zuo, J. Z. Cui, J. Dong and F. X. Yu, Effects of low frequency electromagnetic field on the as-cast microstructures and mechanical properties of superhigh strength aluminum alloy, Mater. Sci. Eng. A. 408 (2005) 176-181.

DOI: 10.1016/j.msea.2005.07.030

[15] X. J. Wang, H. T. Zhang, Y. B. Zuo, Q. F. Zhu and J. Z. Cui, Experimental investigation of heat transport and solidification during low frequency electromagnetic hot-top casting of 6063 aluminum alloy, Mater. Sci. Eng. A. 497 (2008) 416-420.

DOI: 10.1016/j.msea.2008.07.064

[16] X. J. Wang, Z. H. Zhao, Y. B. Zuo and J. Z. Cui, Effects of low frequency electromagnetic field on solidification of 7050 aluminium alloy during hot top casting, Mater. Sci. Tech. 25 (2009) 1207-1210.

DOI: 10.1179/174328408x382172

[17] Q. F. Zhu, Z. H. Zhao, Y. B. Zuo, X. J. Wang and J. Z. Cui, Effect of low frequency electromagnetic field on as casting structure and surface quality of horizontal direct chill casting 7075 alloy, Int. J. Cast. Met. 25 (2012) 93-99.

DOI: 10.1179/1743133611y.0000000019

[18] G. S. Wang, Z. H. Zhao, J. Z. Cui and Q. Guo, Microstructure and mechanical properties of low frequency electromagnetic casting 7075 aluminum alloy, Acta Metall. Sin.(Engl. Lett.) 25 (2) (2012) 160-168.

DOI: 10.1007/s40195-019-00992-2

[19] H. T. Zhang, H. Nagaumi and J. Z. Cui, Mater. Coupled modeling of electromagnetic field, fluid flow, heat transfer and solidification during low frequency electromagnetic casting of 7XXX aluminum alloys: Part 1: Development of a mathematical model and comparison with experimental results, Sci. Eng. A. 448 (2007) 189-203.

DOI: 10.1016/j.msea.2006.10.062

[20] X. L. Liao, Q. J. Zhai, J. Luo, W. J. Chen and Y. Y. Gong, Refining mechanism of the electric current pulse on the solidification structure of pure aluminum, Acta. Mater. 55 (2007) 3103-3109.

DOI: 10.1016/j.actamat.2007.01.014

[21] A. Vogel and B. J. Cantor, Stability of a spherical particle growing from a stirred melt, Cryst. Growth. 37 (1977) 309-316.

DOI: 10.1016/0022-0248(77)90125-7

[22] H. Garabedian, Collision breeding of ice crystals, J. Cryst. Growth. 22 (1974) 188-192.