Microstructure Evolution of AS21 Magnesium Alloy via the SIMA Process

Abstract:

AS is a relatively new series of Magnesium alloys. The microstructure of this alloy can be improved for semisolid processing. The current research is concerned with the microstructure evolution of AS21 under the strain induced melt activated (SIMA) process. For this purpose, the AS21 alloy is cast and compressed 10-40% at 200 °C. The semisolid heat treatment is completed in a carbonate salt bath at different temperatures between 600-620 °C. The microstructure studies show that there is no favourable microstructure evolution between 600-610 °C. At 615 °C fine globular grains are obtained with the most desired mean grain size and sphericity of 67 µm and 81%, respectively. At 620 °C an undesirable coarsening phenomenon occurs that damages the microstructure globularity. SEM micrographs show that in a successful SIMA processing, the Mg₂Si phases are broken into fine particles distributed within the grains and grain boundaries.

• Periodical: Materials Science Forum (Volumes 706-709)
• Pages: 1146-1151
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.706-709.1146
• Online since: January 2012
• Authors: Majid Bigdeli Karimi, Mostafa Hajian Heidary, Javad Samei, Daniel E. Green
• Keywords: Magnesium Alloy, Microstructure, Semi-Solid Processing, SIMA Processing

References

[1] J. Jiang, Y. Wang, and S. Luo: Mater. Character. Vol. 58 (2007), p.190.

[2] J.L. Jorstad: Proceedings of 8th International conference on semisolid processing of alloys and composites, Cyprus (2004), p.15.

[3] S. Ji, Z. Fan, and M.J. Bevis: Mater. Sci. Eng. A Vol. 299 (2001), p.210.

[4] M.C. Flemings: Metall. Mater. Trans. A Vol. 22 (1991), p.269.

[5] E. Tzimas, and A. Zavaliangos, Mater. Sci. Eng. A Vol. 289 (2000), p.217.

[6] J.E. Kelly, E. Kenneth, and K.P. Young, US Patent 5178, 204. (1993).

[7] E. Tzimas, A. Zavaliangos, Mater. Sci. Eng. A Vol. 289 (2000), p.228.

[8] F. Czerwinski, in: Magnesium Injection Molding (Springer, New York, 2008).

[9] P. Mathur, S. Annavarapu, D. Apelian, and A. Lawley: Mat. Sci. Eng. A Vol. 142 (1991), p.261.

[10] H.V. Atkinson: Prog. Mater. Sci. Vol. 50 (2005), p.341.

[11] Y. Sirong, L. Dongcheng, and N. Ki: Mater. Sci. Eng. A Vol. 420 (2006), p.165.

[12] H.Q. Lin, J.G. Wang, H.Y. Wang, and Q.C. Jiang: J. Alloys Compd. Vol. 431 (2007), p.141.

[13] A. Mahdavi, M. Bigdeli, M. Hajian Heidary, and F. Khomamizadeh: Solid State Phenom. Vols. 141-143 (2008), p.367.

DOI: 10.4028/www.scientific.net/ssp.141-143.367

[14] S. Housh, and B. Mikucki, in: Selection and Application of Magnesium and Magnesium Alloys, edited by A. Stevenson, ASM International, Vol. 2 (1993), p.455.

DOI: 10.31399/asm.hb.v02.a0001074

[15] S. Luo, Q. Chen, and Z. Zhao, Mater. Sci. Eng. A Vol. 501 (2009), p.146.

[16] J.G. Wang, H.Q. Lin, Y.Q. Li, and Q.C. Jiang, J. Alloys Compd. Vol. 457 (2008), p.251.

[17] Q.Q. Zhang, Z.Y. Cao, Y. B. Liu, J.H. Wu, and Y.F. Zhang, Mater. Sci. Eng. A Vol. 478 (2008), p.195.

[18] Y.F. Zhang, Y.B. Liu, Z.Y. Cao, Q.Q. Zhang, and L. Zhang, J. Mater. Process. Technol. Vol. 209 (2009), p.1375.

[19] J. Z. Sheng, Y. H. Hu, Z. X. Ping, S.O. Sugiyama, and J. Yanagimoto, J. Mater. Process. Technol. Vol. 202 (2008), p.412.

[20] B. Bronfin, M. Katsi, and E. Aghion, Mater. Sci. Eng. A Vol. 302 (2001), p.46.

[21] W. Blum, P. Zhang and B. Watzinger, B. V. Grossmann, and H. G. Haldenwanger, Mater. Sci. Eng. A Vols. 319-321 (2001), p.735.

[22] J.G. Wang, P. Lu, H.Y. Wang, and Q.C. Jiang, Mater. Lett. Vol. 58 (2004), p.3852.