Microstructural Evolution and Recrystallization Behavior in Copper Multi-Directionally Forged at 77 K

Abstract:

Article Preview

Microstructural evolution in pure copper during multi-directional forging (MDF) at temperature of 77 K was studied. Flow stress during MDF at 77 K showed a monotonical increase at all strain. Ultra fine (sub)grains of 0.15μm in diameter were evolved, which was accompanied by deformation twinning, at strain of Σε = 2.4. In higher strain region, Σε = 6.0, lamellar-look structure of twins extensively appeared. The lamellar spacing was 10-100nm. For comparison, samples were also MDFed at 300 K. The flow stress curves showed an apparent steady state flow at above strain of Σε =2.0, which implies occurrence of dynamic recovery. The evolved (sub)grain size was 0.3 μm at high strain of Σε = 6.0. Therefore, grain refinement seems to take place more easily by MDF at 77 K compared with that at 300 K due to effect of deformation twin. Microstructures evolved under MDF at 77 K and 300 K showed different annealing behavior. Static recrystallization started earlier and faster in the samples MDFed at 77K than those MDFed at 300K.

Info:

Periodical:

Advanced Materials Research (Volumes 15-17)

Edited by:

T. Chandra, K. Tsuzaki, M. Militzer and C. Ravindran

Pages:

649-654

Citation:

Y. Nakao et al., "Microstructural Evolution and Recrystallization Behavior in Copper Multi-Directionally Forged at 77 K", Advanced Materials Research, Vols. 15-17, pp. 649-654, 2007

Online since:

February 2006

Export:

Price:

$38.00

[1] A. Belyakov, T. Sakai, H. Miura, R. Kaibyshev and K. Tsuzaki: Acta Mater., 50 (2002) p.1547.

[2] K. Neishi, T. Uchida, A. Yamauchi, K. Nakamura, Z. Horita and T.G. Langdon: Mater. Sci. Eng. A, 307 (2001) p.23.

[3] N. Tuji, Y. Ito, Y. Saito and Y. Minamo: Scr. Mater., 47 (2002) p.893.

[4] A. Belyakov, T. Sakai, H. Miura and K. Tsuzaki: Philos. Mag. A, 81 (2001) p.2629.

[5] J. Strobrawa, L. Ciura, Z. Rdzawski: Scr. Mater., 34 (1996) p.1759.

[6] Y. Wang, T. Jiao and E. Ma: Mater. Trans., 44 (2003) p. (1926).

[7] Y.F. Shen, L. Liu, Q.H. Liu, Z.H. Jin and K. Liu: Scr. Mater., 52 (2005) p.989.

[8] H. Miura, T. Sakai: Journal of the JRICu, 44 (2005).