Melt Refining Technology of Highly-Contaminated Magnesium Alloy Scraps via a Sequential Refining Process

Abstract:

Steering wheel and headlamp housing scrap are chosen as targets for the development of a refining technology for highly contaminated magnesium melt, because they contain abundant foreign materials, which have high potential to form non-metallic inclusions and to deteriorate the corrosion resistance of recycled alloys. A sequential melt treatment technology has been investigated for refining old scrap. The headlamp housing scrap composed of AZ91D magnesium alloy covered with phosphating and Al-Si deposition layers was successfully refined by repeating gas bubbling without flux addition, whereas prefiltering and fluxing were necessary to refine the steering wheel scrap composed of AM50A magnesium alloy containing 1% polyurethane. However, the corrosion rates of the recovered ingots from the headlamp housing were relatively higher than those from the steering wheel, likely due to the greater concentration of iron with the increased amount of flux.

• Periodical: Materials Science Forum (Volumes 828-829)
• Pages: 82-86
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.828-829.82
• Online since: August 2015
• Authors: Ki Ho Koh, Byoung Gi Moon*, Bong Sun You, Kwang Seon Shin, Nack Kim, K.Y. Sohn
• Keywords: Contamination, Magnesium, Melt Refining, Old Scrap, Recycling

References

[1] G. Hanko, H. Antrekowitsch, and P. Ebner, Recycling Automotive Magnesium Scrap, JOM, 54, 2 (2002) 51-54.

DOI: 10.1007/bf02701075

[2] D. Fechner, N. Hort, C. Blawert, W. Dietzel, and K.U. Kainer, Magnesium Recycling: State-of-the-Art Developments, Part I, Light Metal Age, 67, 4 (2009) 42-46.

[3] H. Antrekowitsch, G. Hanko, and P. Ebner, Recycling of Different Types of Magnesium Scrap, Magnesium Technology 2002, 43-48.

DOI: 10.1007/bf02701075

[4] H.S. Kim, Domestic Magnesium Market Report in 2013, Information on http: /www. kmt. or. kr.

[5] H.S. Kim, Domestic Magnesium Market Report in 2014, Information on http: /www. amenews. kr.

[6] K. Higuchi and K. Nakajima, Closed Loop Recycling of Magnesium PC Housing, Proceedings of IEEE International Symposium on Electronics & the Environment, IEEE, Dallas, USA (1996) 102-108.

DOI: 10.1109/isee.1996.500406

[7] B.G. Moon, B.S. You, and K.H. Koh, Purification of Highly Contaminated Magnesium Melt, Magnesium Technology 2013, John Wiley & Sons, Inc. (2013) 59-63.

DOI: 10.1002/9781118663004.ch10

[8] M. Liang, G. Wu, W. Ding, and W. Wang, Effect of inclusion on service properties of GW103K magnesium alloy, Trans. Nonferrous Met. Soc. China 21 (2011) 717-724.

DOI: 10.1016/s1003-6326(11)60771-1

[9] J. Wang, J. Zhou, W. Tong, and Y. Yang, Effect of purification treatment on properties of Mg-Gd-Y-Zr alloy, Trans. Nonferrous Met. Soc. China 20 (2010) 1235-1239.

DOI: 10.1016/s1003-6326(09)60284-3

[10] H. Gaw, G. Wu, W. Ding, L. Liu, ZX. Zeng, and Y. Zhu, Study on Fe reduction in AZ91 melt by B2O3, Mater. Sci. Eng. A, 368 (2004) 311-317.

DOI: 10.1016/j.msea.2003.11.017

[11] J. Wang, Y. Li, S. Huang, and X. Zhou, Study on the corrosion behavior and the corrosion films on the surfaces of Mg-xSn alloys in 3. 5 wt. % NaCl solution, Appl. Surf. Sci. 317 (2014) 1143-1150.

DOI: 10.1016/j.apsusc.2014.09.040

[12] H.E. Friedrich and B.L. Mordike (Eds. ), Magnesium Technology: Metallurgy, Design Data, Applications, Springer, Berlin, (2005).