Abstract
A new melt conditioned direct chill (MC-DC) casting process has been developed for producing high quality magnesium alloy billets and slabs. In the MC-DC casting process, intensive melt shearing provided by a high shear device is applied directly to the alloy melt in the sump during DC casting. The high shear device provides intensive melt shearing to disperse potential nucleating particles, creates a macroscopic melt flow to distribute uniformly the dispersed particles, and maintains a uniform temperature and chemical composition throughout the melt in the sump. Experimental results have demonstrated that the MC-DC casting process can produce magnesium alloy billets with significantly refined microstructure and reduced cast defects. In this paper, we introduce the new MC-DC casting process, report the grain refining effect of intensive melt shearing during the MC-DC casting process and discuss the grain refining mechanism.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Mordike B L, Ebert T. Magnesium: Properties — applications — potential. Mater. Sci. Eng. A 2001;302:37.
Emley E F. Principles of magnesium technology. Oxford: Pergamon Press, 1966.
Zhang S M, Fan Z, Zhen Z. Direct chill rheocasting (DCRC) of AZ31 Mg alloy. Mater. Sci. Technol. 2006;22:1489.
Qiu D, Zhang M X, Taylor J A, Fu H M, Kelly P M. A novel approach to the mechanism for the grain refining effect of melt superheating of Mg-Al alloys. Acta Mater. 2007;55:1863.
Nadella R, Eskin D G, Katgerman L. Role of grain refining in hot cracking and macrosegregation in direct chill cast AA7075 billetsRole of grain refining in hot cracking and macrosegregation in direct chill cast AA7075 billets. Mater. Sci. Technol. 2007;23:1327.
Eskin D G. Physical metallurgy of direct chill casting of aluminum alloys. Boca Raton CRC Press, 2008.
Murty B S, Kori S A, Chakraborty M. Graun refinement of aluminium and its alloys by heterogeneous nucleation and alloying. Inter. Mater. Rev. 2002;47:3.
David H SJ, Ma Q, Easton M A, Cao P, Hildebrand Z. Grain refinement of magnesium alloys. Metall. Mater. Trans. A 2005;36:1669.
Zhang M X, Kelly P M, Qian M, Taylor JA. Crystallography of grain refinement in Mg-Al based alloys. Acta Mater. 2005;53:3261.
Easton M A, Schiffl A, Yao J-Y, Kaufmann H. Grain refinement of Mg-Al(-Mn) alloys by SiC additions. Scripta Mater. 2006;55:379.
Cui J Z, Zhang Z Q, Le Q C. Direct-chilling casting of Mg alloy under electromagnetic and ultrasonic combined field. Trans. Nonferrous Met. Soc. China 2010;20:s297.
Fan Z, Wang Y, Xia M, Arumuganathar S. Enhanced heterogeneous nucleation in AZ91D alloy by intensive melt shearing. Acta Mater. 2009;57:4891.
Zuo Y B, Li H T, Xia M X, Jiang B, Scamans G M, Fan Z. Refining grain structure and porosity of an aluminium alloy with intensive melt shearing. Scripta Mater. 2011;64:209.
Fan Z, Liu G. Solidification behaviour of AZ91D alloy under intensive forced convection in the RDC process. Acta Mater. 2005;53:4345.
Zuo Y B, Xia M, Liang S, Wang Y, Scamans G, Fan Z. Grain refinement of DC cast AZ91D Mg alloy by intensive melt shearing. Mater. Sci. Technol. 2011;27:101.
Fan Z, Zuo Y B, Jiang B. Apparatus and method for liquid metals treatment. UK patent, Application No. 1015498.7, 2010.
The Aluminium Association. Standard test procedure for aluminium alloy grain refiners (TP-1). Washington DC, USA, 1990.
Mirak A R, Divandari M, Boutorabi S M A, Campbell J. Oxide Film Characteristics of AZ91 Magnesium Alloy in Casting Conditions. Int. J. Cast Met. Res. 2007;20:215.
Campbell J. Entrainment defects. Mater. Sci. Technol. 2006;22:127.
Men H, Jiang B, and Fan Z. Mechanisms of grain refinement by intensive shearing of AZ91 alloy melt. Acta Mater. 2010;58:6526.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2012 TMS (The Minerals, Metals & Materials Society)
About this chapter
Cite this chapter
Zuo, Y.B., Jiang, B., Zhang, Y., Fan, Z. (2012). Melt Conditioned DC (MC-DC) Casting of Magnesium Alloys. In: Mathaudhu, S.N., Sillekens, W.H., Neelameggham, N.R., Hort, N. (eds) Magnesium Technology 2012. Springer, Cham. https://doi.org/10.1007/978-3-319-48203-3_29
Download citation
DOI: https://doi.org/10.1007/978-3-319-48203-3_29
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-48571-3
Online ISBN: 978-3-319-48203-3
eBook Packages: Chemistry and Materials ScienceChemistry and Material Science (R0)