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Strain induced hardening and softening behaviors of deformed Cu and Cu–Ge alloys

Published online by Cambridge University Press:  24 February 2016

Y.L. Gong
Affiliation:
Faculty of Science, Kunming University of Science and Technology, Kunming 650093, Yunan Province, China
H.S. Kim
Affiliation:
Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790-784, South Korea
S.Y. Ren
Affiliation:
Ningbo Powerway Alloy Material Co., Ltd, Ningbo 315135, Zhejiang Province, China
S.D. Zeng
Affiliation:
Department of Thermal Engineering, Yunnan Institute of Measuring and Testing Technology, Kunming 650228, Yunan Province, China
X.K. Zhu*
Affiliation:
Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, Yunan Province, China
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

Herein, Cu and Cu–Ge alloys with different stacking fault energies (SFEs) are prepared via rolling at room temperature (RTR) and via a combination of high-pressure torsion (HPT) and RTR (HPT + RTR). The x-ray diffraction measurements reveal that the grain size, dislocation density, and twin density vary with the strain and SFEs. The tensile tests indicate that the strength of materials with medium SFEs increases initially and then slightly declines, while the ductility is enhanced by increasing the strain via HPT. In contrast, for low-SFE materials, enhanced strength and improved ductility may be achieved simultaneously through increasing the strain to a high level. The variation of strength with respect to strain is primarily dependent on the solute concentration and SFE. The underlying mechanisms governing the effect of strain and SFE on the microstructures and mechanical properties of the metals are also discussed.

Type
Articles
Copyright
Copyright © Materials Research Society 2016 

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References

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