Dynamic Mechanical Properties of Continuously Cast Al Alloy in Electromagnetic Stirrer

Abstract:

The mechanical properties of electromagnetically stirred billet of Al alloy during continuous casting such as a tensile, impact, and fatigue property was examined with respect to a size and roundness of primary α phase to examine the influence of the globularization and refining of primary α phase on the dynamic mechanical property. The billet was continuously cast in a casting speed of 100 to 600 mm/min during the electromagnetic stirring with a magnetic flux density of 700 Gauss and then was heat-treated. All tensile properties were enhanced with decreasing the size of primary α crystal and the ultimate tensile strength (UTS), yield strength, and elongation was obtained 320MPa, 235MPa, and 17.8%, respectively, at a size of primary α phase of 77 um. The fatigue life at fracture was largely improved by 37% from 1.25×105 to 1.7×105 cycles and the fracture toughness was obtained approximately 7.25 joules as a maximum value at a minimum size of primary α phase on the present experiment condition. Therefore, it indicates that all mechanical properties can be improved at the higher casting speed owing to the fine microstructure of a primary α phase and also eutectic phase due to the higher cooling rate.

• Periodical: Solid State Phenomena (Volumes 116-117)
• Pages: 340-343
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.116-117.340
• Online since: October 2006
• Authors: Dock Young Lee, Suk Won Kang, Ki Bae Kim
• Keywords: Aluminium Alloy, Electromagnetic Stirring (EMS), Elongation, Fatigue Property, Fracture Toughness, Primary α Phase

References

[1] D.B. Spencer et al.: Metallurgical Transactions vol. 3 (1972), p. (1925).

[2] M.S. Lewandowski and R.A. Overfelt: Acta Mater. Vol. 47(1999), p.4695.

[3] A.I. Nussbaum: Light Metal Age, June (1996), p.6.

[4] M. Perez et al.: Acta Mater. Vol. 48 (2000), p.3773.

[5] D.H. Kirkwood: Inter. Materials Reviews Vol. 39(1996), p.173.

[6] D.Y. Lee, K.B. Kim, D.H. Kim: Mat. Sci. Forum Vol. 486 (2005), p.338, ibid: Vol. 449 (2004), p.321.

[7] D.Y. Lee, K.B. Kim, H.I. Lee, D.H. Kim: Proc. 65th World Foundry. Congr., Gyeongju, Korea, Oct. 20-24 (2002).