Numerical Simulation of Thixo-co-Extrusion of 7075/AZ91D Double-Layer Tubes

Abstract:

Due to the excellent thermal conductivity and high strength of aluminum alloy and unique advantages containing shock absorbing, vibrations dampening and corrosion resistant of magnesium alloy, Al/Mg double-layer tubes have been widely utilized in household appliances, automobiles, aerospace industries, and high-speed trains in recent years. Conventionally, double-layer tubes are produced by welding, extrusion, hydroforming, magnetic pulse cladding. These processes are either complex or highly energy-consuming. To improve efficiency and reduce energy consumption, a new technology, thixo-co-extrusion (TCE), is put forward for production of double-layer tubes. In this paper, the thixo-co-extrusion of a 7075/AZ91D double-layer tube is investigated by numerical simulation. This study assesses the influences of extrusion velocity, the thickness ratios of two layers, the reheating temperatures of billets and the preheating temperature of die on the flow behaviors. The results show that the extrusion velocity and the thickness ratios significantly influence the contact pressures on the interface as well as the velocity fields. Besides, the reheating temperatures of billets and the preheating temperatures determine the distribution of temperature fields. Under the contact pressures and a certain temperature, atomic diffusion takes place on the interface between inner and outer layer, which leads to metallurgical bonding of the interface. The paper contributes to a better understanding of the thixo-co-extrusion technology for the production of double-layer tubes with desirable mechanical properties.

• Periodical: Solid State Phenomena (Volume 256)
• Pages: 119-125
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.256.119
• Online since: September 2016
• Authors: Xiao Wei Li, Kai Kun Wang*, Jin Long Fu, Fei Yin
• Keywords: Double-Layer Tubes, Interface, Numerical Simulation, Thixo-Co-Extrusion

References

[1] X. Sun, J. Tao, X. Guo, Bonding properties of interface in Fe/Al clad tube prepared by explosive welding, Trans. Nonferrous Met. Soc. China. 21 (2011) 2175–2180.

DOI: 10.1016/s1003-6326(11)60991-6

[2] J.L. Alcaraz, J. Gil-Sevillano, An analysis of the extrusion of bimetallic tubes by numerical simulation, Int. J. Mech. Sci. 38 (1996) 157–173.

DOI: 10.1016/0020-7403(95)00044-x

[3] X. Guo, Z. Liu, H. Wang, L. Wang, F. Ma, X. Sun, et al., Hydroforming simulation and experiment of clad T-shapes, Int. J. Adv. Manuf. Technol. (2015) 1–7.

DOI: 10.1007/s00170-015-7558-4

[4] Z. Fan, H. Yu, C. Li, Plastic deformation behavior of bi-metal tubes during magnetic pulse cladding: FE analysis and experiments, J. Mater. Process. Technol. 229 (2016) 230–243.

DOI: 10.1016/j.jmatprotec.2015.09.021

[5] K.K. Wang, P. Zhang, Y.M. Du, P. Zeng, H.G. Li, Basic Study on Thixo-Co-Extrusion of Multi-Layer Tube with Al/Mg Alloys, Solid State Phenom. 141–143 (2008) 73–78.

DOI: 10.4028/www.scientific.net/ssp.141-143.73

[6] P. Kapranos, T. Haga, E. Bertoli, A. Pola, Z. Azpilgain, I. Hurtado, Thixo-Extrusion of 5182 Aluminium Alloy, Solid State Phenom. 141–143 (2008) 115–120.

DOI: 10.4028/www.scientific.net/ssp.141-143.115

[7] Y.M. Du, K.K. Wang, P. Zhang, C.M. Ma, F. Xu, FEM simulation on extrusion of double-layer tube of aluminum and magnesium alloys, Chin. J. Nonferrous Met. 19 (2009) 208–216.

[8] Y. Du, K.K. Wang, P. Zhang, C.M. Ma, F. Xu, Prospect on thixo-co-extrusion of multi-layer tube [J], Light Alloy Fabr. Technol. 1 (2009) 1.

[9] K.K. Wang, J. Sun, H. Meng, Y. Du, X. Wang, Numerical simulation on thixo-co-extrusion of double-layer tube with A356/AZ91D, Trans. Nonferrous Met. Soc. China. 20, Supplement 3 (2010) s921–s925.

DOI: 10.1016/s1003-6326(10)60607-3

[10] D.H. Kirkwood, M. Suéry, P. Kapranos, H.V. Atkinson, K.P. Young, Semi-solid processing of alloys, Springer, (2010).

DOI: 10.1007/978-3-642-00706-4

[11] F. Zhang, N.N. Song, J. Zhang, Y.L. Kang, Q. Zhu, Numerical Simulation on the Filling Process of Rheological Die Casting and Forming Defects Analysis, Solid State Phenom. 192–193 (2012) 293–298.

DOI: 10.4028/www.scientific.net/ssp.192-193.293

[12] M. Modigell, J. Koke, Time-Dependent Rheological Properties of Semi-Solid Metal Alloys, Mech. Time-Depend. Mater. 3 (1999) 15–30.

[13] L. Yageng, M. Weimin, Z. Wenzhi, Y. Bin, Rheological behavior of semi-solid 7075 aluminum alloy at steady state, Res. Dev. 11 (2014).

[14] Z.S. Zhen, W.M. Mao, S.J. Yan, The apparent viscosity of semi-solid AZ91D alloy at steady state, Acta Metall. Sin. Engl. Lett. 15 (2009) 505–510.