Abstract
Copper-clad aluminum (CCA) flat bars produced by the continuous casting–rolling process were subjected to continuous induction heating annealing (CIHA), and the effects of induction heating temperature and holding time on the microstructure, interface, and mechanical properties of the flat bars were investigated. The results showed that complete recrystallization of the copper sheath occurred under CIHA at 460°C for 5 s, 480°C for 3 s, or 500°C for 1 s and that the average grain size in the copper sheath was approximately 10.0 μm. In the case of specimens subjected to CIHA at 460–500°C for longer than 1 s, complete recrystallization occurred in the aluminum core. In the case of CIHA at 460–500°C for 1–5 s, a continuous interfacial layer with a thickness of 2.5–5.5 μm formed and the thickness mainly increased with increasing annealing temperature. After CIHA, the interfacial layer consisted primarily of a Cu9Al4 layer and a CuAl2 layer; the average interface shear strength of the CCA flat bars treated by CIHA at 460–500°C for 1–5 s was 45–52 MPa. After full softening annealing, the hardness values of the copper sheath and the aluminum core were HV 65 and HV 24, respectively, and the hardness along the cross section of the CCA flat bar was uniform.
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Y.J. Su, X.H. Liu, Y.F. Wu, H.Y. Huang, and J.X. Xie, Numerical simulation of temperature field in horizontal core-filling continuous casting for copper cladding aluminum rods, Int. J. Miner. Metall. Mater., 20(2013), No. 7, p. 684.
A. Gibson, Emerging applications for copper-clad steel and aluminum wire, Wire J. Int., 41(2008), No. 2, p. 142.
Y.F. Wu, X.H. Liu, and J.X. Xie, Rolling process and properties of copper cladding aluminum flat bars using continuous casting bars with the rectangle section, J. Univ. Sci. Technol. Beijing, 34(2012), No. 11, p. 1301.
Y.Z. Wu, Y.Q. Ma, S.Y. Liu, and Y. Zhang, Machining procedure and solid-state bonding mechanism of clad-process welding copper clad aluminum wire, Weld. Joining, 4(2006), p. 40.
Y.Q. Ma, Y.Z. Wu, H.T. Gao, Y. Zhang, and S.Y. Liu, Microstructure and mechanical properties of copper clad aluminium wire by drawing at room temperature, Key Eng. Mater., 334-335(2007), p. 317.
Y.K. Dai, Characteristics of aluminium conductor sheathed by copper and its application to transformer winding, Transformer, 43(2006), No. 6, p. 12.
M. Hiderita, T. Yamaguchi, and T. Takayama, Method of Producing Copper Clad Aluminum, US Patent, Appl. 314912, 1972.
J. Hu, The stady to produce copper fold aluminum composite wire by hydraulic extrusion, New Technol. New Process, (2001), No. 9, p. 27.
K.Y. Rhee, W.Y. Han, H.J. Park, and S.S. Kim, Fabrication of aluminum/copper clad composite using hot hydrostatic extrusion process and its material characteristics, Mater. Sci. Eng. A, 384(2004), No. 1-2, p. 70.
J.M. Story, B. Avitzur, and W.C. Hahn, The effect of receiver pressure on the observed flow pattern in the hydrostatic of bimetal rods, J. Eng. Ind., 98(1976), No. 3, p. 909.
C.G. Kang, Y.J. Jung, and H.C. Kwon, Finite element simulation of die design for hot extrusion process of Al/Cu clad composite and its experimental investigation, J. Mater. Process. Technol., 124(2002), No. 1-2, p. 49.
K. Osakada, M. Limb, and P.B. Mellor, Hydrostatic extrusion of composite rods with hard cores, Int. J. Mech. Sci., 15(1973), No. 4, p. 291.
J.X. Xie, X.H. Liu, X.F. Liu, and Y.J. Su, Horizontal Continuous Direct Composite Cast Forming Equipment and Technology of Cladding Materials, Chinese Patent, Appl. 200610112817.3, 2006.
J.X. Xie, X.H. Liu, X.F. Liu, and Y.B. Luo, A High Performance Rectangle Cross Section Copper Cladding Aluminum Composite Electric Bus-bar and Manufacturing Process, Chinese Patent, Appl. 200810057668.4, 2008.
Y.J. Su, X.H. Liu, X.F. Liu, and J.X. Xie, Interfacial microstructure and bonding strength of copper cladding aluminum rods fabricated by horizontal core-filling continuous casting, Metall. Mater. Trans. A, 42(2011), No. 13, p. 4088.
Y.J. Su, X.H. Liu, C.J. Wu, X.F. Liu, and J.X. Xie, Effects of processing parameters on the fabrication of copper cladding aluminum rods by horizontal core-filling continuous casting, Metall. Mater. Trans. B, 42(2010), No. 1, p. 104.
J.X. Xie, X.H. Liu, and H.Y. Huang, Horizontal core-filling continuous casting of copper clad aluminum conductor materials: properties and applications, Light Met. Age, 73(2015), No. 1, p. 64.
Y.F. Wu, X.H. Liu, and J.X. Xie, Effect of annealing temperature on texture and properties of copper cladding aluminum flat bar fabricated by continuous casting and subsequent rolling technology, Chin. J. Nonferrous Met., 24(2014), No. 1, p. 188.
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Liu, Xh., Jiang, Yb., Zhang, Hj. et al. Effect of continuous induction annealing on the microstructure and mechanical properties of copper-clad aluminum flat bars. Int J Miner Metall Mater 23, 1427–1436 (2016). https://doi.org/10.1007/s12613-016-1366-1
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DOI: https://doi.org/10.1007/s12613-016-1366-1