Plastic deformation of 7075 Aluminum Alloy using Integrated Extrusion-Equal Channel Angular Pressing

Subject Areas : Chemistry

mehdi  shaban ¹ (sahand university of technology)
sahel  gozalzadeh ² (Department of Materials Engineering, Sahand University of Technology, Tabriz, Iran)
beitallah  eghbali ³ (Department of Materials Engineering, Sahand University of Technology, Tabriz, Iran)

Received: 2016-02-25 Accepted : 2016-03-16 Published : 2016-03-01

Keywords: Finite element simulation, Severe plastic deformation, 7075 aluminum alloy,

Abstract :

Grain refinement improves the mechanical properties and formability of metals and alloys. So far, several different grain refinement methods have been proposed and studied. Severe plastic deformation is one of the most promising and efficient methods. Therefore, in the present study the possibility of imposing a two-step severe plastic deformation (Extrusion and Equal channel angular pressing) on AA7075 alloy using a special designed die is investigated. Using this method, a very coarse grained microstructure with grain size of 94µm is refined to grain size of 7.5µm. Also, microstructural developments during severe deformation with and without preheating are investigated. Plastic strain distribution and temperature variation inside deformed samples are predicted by the use of thermal coupled displacement 3D finite element method. Results of FEM simulations clearly showes that the plastic strain distribution and temperature is non-uniform in sample and this introduces inhomogeneity in the resultant microstructure of sample at different regions.

References:

[1] A.K. Giumelli, M. Militzer, “Analysis of the Austenite Grain Size Distribution in Plain Carbon Steels”, ISIJ Int., Vol. 39, 1999, pp. 271–280.

[2] R.Z. Valiev, Y. Estrin, Z. Horita, T.G. Langdon, M. J. Zehetbauer, Y. T. Zhu,“Producing bulk ultrafine-grained materials by severe plastic deformation “, JOM., Aprill 2006,  pp. 33-39.

[3] T.C. Lowe, R.Z. Valiev, “The use of severe plastic deformation techniques in grain refinement”, JOM., October 2004, pp. 64-77.           

[4] Z. Horita, M. Furukawa, M. Nemoto, T.G. Langdon, “Development of fine grained structures using severe plastic deformation”, Mater. Sci. Technol., Vol. 16, 2000, pp. 1239-1245.       

[5] R.Z. Valiev, T.G. Langdon, “Principles of equal-channel angular pressing as a processing tool for grain refinement “, Prog Mater. Sci., Vol. 51, 2006, pp. 881–981.

[6] Azushima, R. Kopp, A. Korhonen, D.Y. Yang, F. Micari, G.D. Lahoti, P. Groche, J. Yanagimoto, N. Tsuji, A. Rosochowski, A. Yanagida,” Severe plastic deformation (SPD) processes for metals”, CIRP Ann- Manuf. Techn., Vol. 57, 2008, pp. 716–735.

[7] M. Furukawa, Z. Horita, M. Nemoto, T.G. Langdon, “Processing of metals by equal-channel angular pressing”, J. Mater. Sci., Vol. 36, 2001, pp. 2835-2843. 

[8] D. Nagarajan, U. Chakkingal, P. Venugopal,” Influence of cold extrusion on the microstructure and mechanical properties of an aluminium alloy previously subjected to equal channel angular pressing “, J. Mater. Proc. Technol., Vol. 182, 2006, pp.  363–8.

[9] Z.C. Duan, N.Q. Chinh, C. Xu, T. G.Langdon, “Developing Processing Routes for the Equal-Channel Angular Pressing of Age-Hardenable Aluminum Alloys“, Metall Mater. Trans. A., Vol. 41, 2010,  pp. 802-809.

[10]  N.Q.Chinh, J. Gubicza, T. Czeppe, J. Lendvai, C. Xu, R.Z.Valiev, T.G.langdon, “Developing a strategy for the processing of age-hardenable alloys by ECAP at room temperature“,  Mater. Sci. Eng. A., Vol. 516, 2009, pp. 248-252.

[11]  M. Furukawa, Z. Horita, M. Nemoto, T. G. Langdon, “Processing of metals by equal-channel angular pressing”, J. Mater. Sci., 36, 2001, 2835-2843.

[12]  Q.X. Pei, C. Lu, M.W. Fu, “Coupled Thermo-Mechanical Analysis of Severe Plastic Deformation for Producing Bulk Nanostructured Materials”, Adv. Eng. Mater., Vol. 6, 2004, pp. 933-936.        

[13]  Y. Yang, Y. Zeng, Z.W. Gao,” Numerical and experimental studies of self-organization of shear bands in 7075 aluminium alloy”, Mater. Sci. Eng. A., Vol. 496, 2008, pp. 291-302.

[14]  Y. Yang, D.H. Li, H.G. Zheng, X.M. Li, F. Jiang,“Self-organization behaviors of shear bands in 7075 T73 and annealed aluminum alloy”, Mater. Sci. Eng. A., Vol. 527, 2009, pp. 344-354.