Melt Conditioned Twin Roll Casting (MC-TRC) for Aluminium Alloys

Abstract:

Twin roll casting (TRC) has been demonstrated to be an effective route for producing Al sheet at a reduced cost. However, the quality of the Al alloys sheets produced by the TRC process is limited by the formation of centreline segregation, which hampers the downstream processing, degrade the mechanical performance of the final rolled products, limit TRC to dilute alloys with a narrow freezing range, and hence prevent its application in a wide range of engineering sectors. To improve the quality of the TRC strips, a new technology, melt conditioning twin roll casting (MC-TRC) has been developed. It has been demonstrated that the MC-TRC process is capable of producing Al-alloy strips with minimal centerline segregation which is attributed to enhanced nucleation by well dispersed naturally occurring oxides in liquid Al alloys. This work aims to investigate the upper composition limit allowed for the MC-TRC process using the binary Al-Mg alloys as model alloys. The results showed that melt conditioning increases the range of alloys (solute content up to 7%) that can be twin roll cast without severe segregation.

• Periodical: Materials Science Forum (Volumes 794-796)
• Pages: 1115-1120
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.794-796.1115
• Online since: June 2014
• Authors: Nilam S. Barekar*, Sanjeev Das, Zhong Yun Fan
• Keywords: Al Alloy, Grain Refinement, Oxide, Segregation, Twin Roll Casting

References

[1] M. Dündar, O. Keles, G. Anger, Production of twin roll cast AA6016 for automotive applications, in: H. R. Müller (Ed. ), Proceedings of the International Conference on Continuous Casting of Non-Ferrous Metals, Wiley-VCH Verlag GmbH & Co., Germany, 2006, pp.87-94.

DOI: 10.1002/9783527607969.ch10

[2] P. A. Friedman, A. M. Sherman, Investigation of continuous cast 5754 and 6111 Al alloys for potential automotive applications, in: S. K. Das (Ed. ) Automotive Alloys II, TMS, San Antonio, Texas, 1998, pp.147-160.

[3] E. F. Emley, Continuous casting of aluminium. Inter. Mater. Rev. (1976) 75-115.

[4] M. Ferry, Direct strip casting of metals and alloys – processing, microstructure and properties, Woodhead Publishing, Ltd., Cambridge, (2006).

[5] R. Cook, P. G. Grocock. P. M. Thomas, D. V. Edmonds, J. D. Hunt, Development of the twin-roll casting process, J. Mater. Process. Technol. 55 (1995) 76-84.

DOI: 10.1016/0924-0136(95)01788-7

[6] A. L. Greer, Control of grain size in solidification, in: B. Cantor, K. A. Q. O'Reilly (Eds. ), Solidification and Casting, Institute of Physics Publishing, Bristol and Philadelphia, 2003, p.214.

[7] B. S. Murty, S. A. Kori, M. Chakraborty, Grain refinement of aluminium and its alloys by heterogeneous nucleation and alloying, Inter. Mater. Rev. 47 (1) (2002) 3-29.

DOI: 10.1179/095066001225001049

[8] Z. Bian, I. Bayandorian, H. Zhang, G. M. Scamans, Z. Fan, Extremely fine and uniform microstructure of magnesium AZ91D alloy sheets produced by melt conditioned twin roll casting, Mater. Sci. Technol. 25(5) (2009) 599-606.

DOI: 10.1179/174328408x326129

[9] S. Kumar, N. HariBabu, G. M. Scamans, Z. Fan, Microstructural evaluation of melt conditioned twin roll cast Al–Mg alloy, Mater. Sci. Technol. 27(12) (2011) 1833-1839.

DOI: 10.1179/1743284710y.0000000044

[10] H. -T. Li, Y. Wang, Z. Fan, Mechanisms of enhanced heterogeneous nucleation during solidification in binary al–mg alloys, Acta. Mater. 60 (2012) 1528-1537.

DOI: 10.1016/j.actamat.2011.11.044

[11] R. E. Sanders, Jr. Technology innovation in aluminium products, JOM 53(2) (2001) 21-25.

[12] J. Patel, Y. Zuo, Z. Fan, Liquid metal engineering by application of intensive melt shearing, in M. J. M. Krane, A. Jardy, R. L. Williamson, J. J. Beaman (Eds. ), Proceedings of the 2013 International Symposium on Liquid Metal Processing and Casting, TMS, Austin, Texas, 2013, pp.291-299.

DOI: 10.1002/9781118830857.ch42

[13] S. A. Lockyer, M. Yun, J. D. Hunt, D.V. Edmonds, Micro- and macro defects in thin sheet twin-rollcast aluminum alloys, Mater. Char. 37 (1996) 301-310.

DOI: 10.1016/s1044-5803(97)80019-8

[14] Y. Wang, H. -T. Li, Z. Fan, Oxidation of aluminium alloy melt and inoculation by oxide particles, Trans. Indian Inst. Met. 65(6) (2012) 653-661.

DOI: 10.1007/s12666-012-0194-x

[15] Z. Fan, An epitaxial model for heterogeneous nucleation on potent substrates, Metall. Mater. Trans. A 44 (2013) 1409-1418.

DOI: 10.1007/s11661-012-1495-8