Application Research of a New Coupling Stirring on DC Casting Process for Large-Sized Aluminum Ingots

Abstract:

A new coupling stirring technology was proposed and used to prepare direct chill (DC) ingots. Ingots of 7075 alloy were produced by a process of normal direct chill (NDC) casting and coupling-stirring direct chill (CDC) casting, respectively. The effect of the technology on the microstructures, composition segregation and mechanical properties of the ingots was investigated. The results showed that the temperature variation in the CDC casting process was more uniform than that in the NDC casting process. The grain of the CDC ingots was finer and more spherical than the grain of NDC ingots. The grain size at the edge, 1/2 radius, and center position in CDC ingot decrease by 28%, 22%, and 24% comparing with the grain size of the corresponding positions of NDC ingot, respectively. The billets with higher performance and lower macro-segregation were obtained in case of CDC. The flow stresses and the difference in different positions of DC ingots measured at Gleeble-1500D thermo-mechanical simulator decreased obviously when the coupling stirring technology is used in the casting process.

• Periodical: Materials Science Forum (Volume 817)
• Pages: 48-54
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.817.48
• Online since: April 2015
• Authors: Hai Jun Wang*, Jun Xu, Zhi Feng Zhang, Bo Liang, Ming Wei Gao
• Keywords: 7075 Alloy, Coupling Stirring, Direct Chill Casting, Large Ingot

References

[1] N.A. Belov, D.G. Eskin, A.A. Aksenov, Multicomponent Phase Diagrams: Applications for Commercial Aluminum Alloys (Elsevier Ltd., Amsterdam, 2005).

[2] F. Xie, X. Yan, L. Ding, F. Zhang, S. Chen, M.G. Chu, Y.A. Chang, A study of microstructure and microsegregation of aluminum 7050 alloy, Mater. Sci. Eng. A, 355(2003) 144-153.

DOI: 10.1016/s0921-5093(03)00056-x

[3] R.K. Paramatmuni, K.M. Chang, B.S. Kang, X.B. Liu, Evaluation of cracking resistance of DC casting high strength aluminum ingots, Mater. Sci. Eng. A 379 (2004) 293-301.

DOI: 10.1016/j.msea.2004.02.026

[4] M. Lalpoor, D.G. Eskin, D. Ruvalcaba, Cold cracking in DC-cast high strength aluminum alloy ingots: An intrinsic problem intensified by casting process parameters, Mater. Sci. Eng. A 528 (2011)2831-2842.

DOI: 10.1016/j.msea.2010.12.040

[5] S. Asai, Birth and recent activities of electromagnetic processing of materials, ISIJInt, 29(1989) 981-992.

DOI: 10.2355/isijinternational.29.981

[6] X. Ban, T.T. Meek, Q. Han, Refinement of eutectic silicon phase of aluminum A356 alloy using high intensity ultrasonic vibration, Scripta Mater. 54(2006) 893-896.

DOI: 10.1016/j.scriptamat.2005.11.004

[7] C.G. Kang, J.W. Bae, B.M. Kim, The grain size control of A356 aluminum alloy by horizontal electromagnetic stirring for rheology forging, J. Mater. Process. Tech. 187-188(2007) 344-348.

DOI: 10.1016/j.jmatprotec.2006.11.181

[8] E.J. Zoqui, M. Paes, E. Es-Sadiqi, Macro-and microstructure analysis of SSM A356 produced by electromagnetic stirring, J. Mater. Process. Tech. 120(2002)365-373.

DOI: 10.1016/s0924-0136(01)01148-7

[9] S. Steinbach, L. Ratke, The effect of rotating magnetic fields on the microstructure of directionally solidified Al-Si-Mg alloy, Mater. Sci. Eng. A 413-414(2005) 200-204.

DOI: 10.1016/j.msea.2005.09.010

[10] Z.F. Zhang, J. Xu, Z.F. Tian, L.K. Shi, The continuous casting of a semisolid aluminum alloy billet with a multiple magnetic field imposed, J. Ceram. Process. Res. 7 (2006)152-155.

[11] Q.M. Jia, Y.L. Zheng, J.Y. Chen, Electromagnetics, Beijing: Higher Education Press, 2001: 262.

[12] J.Z. Liu, Dynamic analysis on the formation of velocity gradient of adhesive fluid. J. Shenyang Inst. Eng. (Nat. Sci. ) 9(2013) 242-245.

[13] Cheng X R, Zhang Z F, Liang B, Effect of annular electromagnetic stirring (A-EM S) on the microstructure ofA357 aluminum alloy, J. Univ. Sci. Technol. Beijing 32 (2010)1175-1180.