Microstructure of Friction Stir Processed Mg-Y-Zn Alloy


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Friction stir processing (FSP) is the effective method of the grain refinement for light metals. The aim of this study is to acquire the fine grained bulk Mg-Y-Zn alloy by ingot metallurgy route much lower in cost. Such bulk alloy can be formed by the superplastic forging. The microstructure of as-cast Mg-Y-Zn alloy was dendrite. The dendrite arm spacing was 72.5 [(m], and there are the lamellar structures in it. FSP was conducted on allover the plate of Mg-Y-Zn alloy for both surfaces by the rotational tool with FSW machine. The stirring passes were shifted half of the probe diameter every execution. The dendrite structures disappeared after FSP, but the lamellar structure could be observed by TEM. The matrix became recrystallized fine grain, and interdendritic second phase particles were dispersed in the grain boundaries. By using FSP, cast Mg-Y-Zn alloy could have fine-grained. This result compared to this material produced by equal channel angular extrusion (ECAE) or rapid-solidified powder metallurgy (RS P/M). As the result, as-FSPed material has the higher hardness than materials produced by the other processes at the similar grain size.



Materials Science Forum (Volumes 558-559)

Edited by:

S.-J.L. Kang, M.Y. Huh, N.M. Hwang, H. Homma, K. Ushioda and Y. Ikuhara




T. Morishige et al., "Microstructure of Friction Stir Processed Mg-Y-Zn Alloy", Materials Science Forum, Vols. 558-559, pp. 777-780, 2007

Online since:

October 2007




[1] E. Abe, Y. Kawamura, K. Hayashi and A. Inoue: Acta Mater. 50(2002) p.3845.

[2] D. H. Bae, M. H. Lee, K. T. Kim, W. T. Kim and D. H. Kim: J. Alloy of Compounds 342(2002) p.445.

[3] H. Watanabe, T. Mukai, K. Ishikawa, S. Kamado, Y. Kojima and K. Higashi: Mater. Trans. 44(2003) p.463.

[4] H. Watanabe, H. Somekawa and K. Higashi: J. Mater. Res. 20(2005) p.93.

[5] R. S. Mishra and Z. Y. Ma: Mater. Sci. R50(2005) p.1.

[6] S. R. Sharma, Z. Y. Ma and R. S. Mishra: Scr. Mater. 53 (2005) p.75.

[7] Y. S. Sato, H. Kokawa: Metall. Mater. Trans. A32 (2001) p.3023.

[8] T. Morishige, M. Tsujikawa, S. Oki, M. Kamita, S. W. Chung and K. Higashi: Mater. Sci. Forum, in press Fig. 4 Vickers hardness distribution of SZ 0 20 40 60 80 100 120 - 10 - 5 0 5 10 Distance from processing center / mm Hardness (HV) Advancing side Retreating side BM BM Single SZ Single SZ Overlapped SZ.