Upsetting of Ultrafine-Grained Bulk Al-Mg Alloy Consolidated by Hydrostatic Extrusion


Article Preview

Deformation characteristics and forming limit of ultrafine-grained bulk Al-Mg alloy were examined with upsetting process. The Al-7.5%Mg alloy produced by cryogenic milling and HIP was subjected to hot hydrostatic extrusion as a final consolidation in fabricating the ultrafine-grained bulk material. Upsetting was performed to study their mechanical characteristics in a practical forming process. The extruded specimen showed that the pores remained in spite of the HIP had been collapsed and almost eliminated. The effective removal of the distributed pores resulted in significant increase of formability by preventing early cracking. Metallographic investigations showed that the size of grain remained below a few hundred nanometer scale in the processes.



Advanced Materials Research (Volumes 26-28)

Edited by:

Young Won Chang, Nack J. Kim and Chong Soo Lee




E.Z. Kim et al., "Upsetting of Ultrafine-Grained Bulk Al-Mg Alloy Consolidated by Hydrostatic Extrusion", Advanced Materials Research, Vols. 26-28, pp. 719-722, 2007

Online since:

October 2007




[1] M. Yu. Gutkin, I. A. Ovid'ko: Plastic Deformation in Nanocrystalline Materials (Springer- Verlag, Berlin 2004).

[2] Y. Wang, M. Chen, F. Zhou, and E. Ma: Nature, Vol. 419 (2002), p.912.

[3] R. Valiev: Nature Materials, Vol. 3 (2004), p.511.

[4] C. Suryanarayana: Mechanical Alloying and Milling (Marcel Dekker, New York 2004).

[5] D. B. Witkin, and E. J. Lavernia: Progress in Materials Science, Vol. 51 (2006), p.1.

[6] S. Lee, C. Y. Yoon, H. J. Park, S. S. Kim, E. Z. Kim, T. H. Choi, and K. Y. Rhee: Journal of Materials Processing Technology, Vol. 191, Issues 1-3, (2007), p.396. 200㎛㎛㎛㎛ 200㎛㎛㎛㎛ (a) (b).