Melt Conditioned Twin Roll Casting (MC-TRC) of Thin Mg-Alloy Strips for Direct Stamping of Mg Components

Abstract:

In this paper we introduce a novel process for the production of thin-walled magnesium components by direct stamping of twin roll cast thin Mg strips. In this process, the melt conditioned twin roll casting (MC-TRC) process is used to produce thin Mg strips (thickness <2 mm) which have a fine equiaxed grain structure and little basal texture and, more importantly, are free from centreline segregation. Such thin Mg strips can be used for thin-walled component production by direct stamping without any rolling. A major advantage of this process is that it circumvents the low formability problem inherently associated with Mg based alloys. In this paper, AZ31 alloy is used to demonstrate this new process. For both TRC and MC-TRC strips, we will analyze the microstructures, assess the mechanical performance at elevated temperatures and conduct hot stamping in the as-cast condition without any prior rolling.

• Periodical: Materials Science Forum (Volume 765)
• Pages: 170-174
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.765.170
• Online since: July 2013
• Authors: Sanjeev Das, Shouxun Ji, Omer El Fakir, Li Liang Wang, John P. Dear, Jian Guo Lin, Ian Stone, Geoff Scamans, Zhong Yun Fan
• Keywords: Magnesium Alloy, Melt Conditioning, Microstructure, Stamping, Twin Roll Casting (TRC)

References

[1] N. Stanford, M.R. Barnett, Fine grained AZ31 produced by conventional thermo-mechanical processing, J. Alloy. Compd. 466 (2008) 182–88.

DOI: 10.1016/j.jallcom.2007.11.082

[2] M.R. Barnett, N. Stanford, P. Cizek, A. Beer, Z. Xuebin, Z. Keshavarz, Mechanism of deformation in magnesium alloys and the challenge of extending room temperature plasticity, JOM 61 (2009) 19–24.

DOI: 10.1007/s11837-009-0115-6

[3] M. Ferry, Direct strip casting of metals and alloys, Woodhead Publishing Ltd., Cambridge, 2006.

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

DOI: 10.1179/174328408x326129

[5] W. Xia, Z. Chen, D. Chen, S. Zhu, Microstructure and mechanical properties of AZ31 magnesium alloy sheets produced by differential speed rolling, J. Mater. Process. Tech. 209 (2009) 26-31.

DOI: 10.1016/j.jmatprotec.2008.01.045

[6] S.B. Kang, J. Cho, L. Chang, Y. Wang, Influence of twin roll casting and differential speed rolling on microstructure and tensile properties in magnesium alloy sheets, Procedia Engineering 10 (2011) 1190-1195.

DOI: 10.1016/j.proeng.2011.04.198

[7] Y. Wang, S.B. Kang, J. Cho, Microstructure and mechanical properties of Mg-Al-Mn-Ca alloy sheet produced by twin roll casting and sequential warm rolling, J. Alloy. Compd. 509 (2011) 704-711.

DOI: 10.1016/j.jallcom.2010.07.183

[8] D. Liang, W. Borbidge, D.R. East, R.V. Allen: US Patent No.7,028,749 B2, 2006.

[9] Z. Fan, G. Liu, Solidification behaviour of AZ91D alloy under intensive forced convection in the RDC process, Acta Mater. 53 (2005) 4345–4357.

DOI: 10.1016/j.actamat.2005.05.033

[10] I. Bayandorian, Y. Huang, Z. Fan, S. Pawar, X. Zhou, G.E. Thompson, The impact of melt-conditioned twin-roll casting on the downstream processing of an AZ31 magnesium alloy, Metall. Mater. Trans. A 43 (2012) 1035-1047.

DOI: 10.1007/s11661-011-1006-3

[11] S. Das, N.S. Lim, J.B. Seol, H.W. Kim, C.G. Park, Effect of the rolling speed on microstructure and mechanical properties of aluminium-magnesium alloys prepared by twin roll casting, Materials and Design 31 (2010) 1633-1638.

DOI: 10.1016/j.matdes.2009.08.032

[12] Z. Fan, Y. Wang, M. Xia, S. Arumuganathar, Enhanced heterogeneous nucleation in AZ91D alloy by intensive melt shearing, Acta Mater. 57 (2009) 4891-4901.

DOI: 10.1016/j.actamat.2009.06.052