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Microstructure and properties of high-conductivity, super-high-strength Cu–8.0Ni–1.8Si–0.6Sn–0.15Mg alloy

Published online by Cambridge University Press:  31 January 2011

Z. Li*
Affiliation:
School of Materials Science and Engineering, Central South University, Changsha 410083, China; and Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Changsha 410083, China
Z.Y. Pan
Affiliation:
School of Materials Science and Engineering, Central South University, Changsha 410083, China
Y.Y. Zhao
Affiliation:
Department of Engineering, University of Liverpool, Liverpool L69 3GH, United Kingdom
M.P. Wang
Affiliation:
School of Materials Science and Engineering, Central South University, Changsha 410083, China
*
a) Address all correspondence to this author. e-mail: lizhou6931@163.com
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Abstract

A high-conductivity and super-high-strength alloy, Cu-8.0Ni-1.8Si-0.6Sn-0.15Mg, has been developed. The processing conditions of the alloy have been investigated. The evolution of microstructure of the alloy on aging has been examined by transmission electron microscopy. The processing condition giving the highest hardness and good electrical conductivity is as follows: solution treatment at 970 °C for 4 h, cold rolling to 60% reduction, and aging at 500 °C for 30 min. The processed alloy has an average tensile strength of 1180 MPa, 0.2% proof strength of 795 MPa, elongation of 2.75%, and average electrical conductivity of 26.5% IACS. Orthorhombic Ni2Si precipitates are responsible for the age-hardening effect. The orientation relationship between the precipitates and the matrix is (110)m(211)p and. DO22 ordering together with spinodal decomposition also contributed to the hardening.

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Articles
Copyright
Copyright © Materials Research Society 2009

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References

1Lehtinen, P., Tiainen, T., and Laakso, L.: New continuously cast CuNiSn alloys provide excellent strength and high electrical conductivity. Metall. (Germany) 50(4), 267 (1996).Google Scholar
2Masamichi, M. and Yoshikiyo, O.: Influence of solution-treatment conditions on the cellular precipitation in Si-doped Cu-10Ni-8Sn alloy. Mater. Trans., JIM 32(12), 1135 (1991).Google Scholar
3Tsubakino, H., Nozato, R., and Yamamoto, A.: Precipitation sequence for simultaneous continuous and discontinuous modes in Cu-Be binary alloys. Mater. Sci. Technol. 19(4), 288 (1993).CrossRefGoogle Scholar
4Masamichi, M. and Yoshikiyo, O.: Effect of B additions on the intragranular and celluar precipitations in a Cu-Be alloy. Mater. Trans., JIM 29(11), 903 (1988).Google Scholar
5Soffa, W.A. and Laughlin, D.E.: High-strength age hardening copper–titanium alloys: Redivivus. Prog. Mater. Sci. 49, 347 (2004).CrossRefGoogle Scholar
6Nagarjuna, S., Balasubramanian, K., and Sarma, D.S.: Effects of cold work on precipitation hardening of Cu-4.5mass% Ti alloy. Mater. Trans., JIM 36, 1058 (1995).CrossRefGoogle Scholar
7Fujiwara, H.: Effect of alloy composition on precipitation behavior in Cu-Ni-Si alloys. J. Jpn. Inst. Met. 62(4), 301 (1998).CrossRefGoogle Scholar
8Ryu, H.J., Baik, H.K., and Hong, S.H.: Effect of thermomechanical treatments on microstructure and properties of Cu-base leadframe alloy. J. Mater. Sci. 35, 3641 (2000).CrossRefGoogle Scholar
9Suzuki, S., Shibutani, N., Mimura, K., Isshiki, M., and Waseda, Y.: Improvement in strength and electrical conductivity of Cu-Ni-Si alloys by aging and cold rolling. J. Alloys Compd. 417, 116 (2006).CrossRefGoogle Scholar
10Nagayoshi, H., Nishijima, F., and Watanabe, C.: Bend formability and microstructure in a Cu-4 mass%Ni-1 mass%Si-0.02 mass%P alloy. J. Jpn. Inst. Met. 70(9), 750 (2006).CrossRefGoogle Scholar
11Monzen, R. and Watanabe, C.: Microstructure and mechanical properties of Cu-Ni-Si alloys. Mater. Sci. Eng., A 483–484, 117 (2008).CrossRefGoogle Scholar
12Zhao, D.M., Dong, Q.M., and Liu, P.: Structure and strength of the age hardened Cu–Ni–Si alloy. Mater. Chem. Phys. 79, 81 (2003).CrossRefGoogle Scholar
13Suzuki, S., Shibutani, N., Mimura, K., Isshiki, M., and Waseda, Y.: Improvement in strength and electrical conductivity of Cu-Ni-Si alloys by aging and cold rolling. J. Alloys Compd. 417, 116 (2006).CrossRefGoogle Scholar
14Monzen, R., Watanabe, C., Zhang, Z.G., and Monzen, R.: Micro-structure and mechanical properties of Cu-Ni-Si alloys. J. Soc. Mat. Sci. Jpn. 54, 717 (2005).Google Scholar
15Zhao, J.C. and Notis, M.R.: Spinodal decomposition, ordering transformation, and discontinuous precipitation in a Cu-15Ni-Sn alloy. Acta Mater. 46(12), 4203 (1998).CrossRefGoogle Scholar
16Goudeau, Ph., Naudon, A., and Welter, J.M.: Anomalous small-angle x-ray scattering study of the early stages of decomposition in Cu-15wt%Ni-8wt%Sn. J. Appl. Crystallogr. 266, 23 (1990).Google Scholar
17William, E.: Hardening during the late stages of spinodal decomposition. Mater. Sci. Eng. 77, 27 (1986).Google Scholar
18Kim, S.S., Rhu, J.C., and Jung, Y.C.: Aging characteristics of thermomechanically processed Cu-9Ni-6Sn alloy. Scr. Mater. 40 (1), 1 (1999).CrossRefGoogle Scholar
19Mabuchi, M.: Strengthening mechanism of Mg-Si alloy. Acta Mater. 44(11), 4611 (1996).CrossRefGoogle Scholar
20Lee, J., Jung, J.Y., Lee, E.S., Park, W.J., Ahn, S., and Kim, N.J.: Microstructure and properties of titanium boride dispersed Cu alloys fabricated by spray forming. Mater. Sci. Eng., A 277, 274 (2000).CrossRefGoogle Scholar