^{1}Department of Mechanical Engineering, University of Tabriz, Tabriz, Iran

^{2}Department of Mechanical Engineering, University of Tabriz

^{3}Department of Mechanical Engineering, College of Engineering, University of Tehran

Abstract

Production of lightweight metals with a higher strength to weight ratio is always the main goal of researchers. In this article, equal channel multi angular pressing (ECMAP) process as one of the most appealing severe plastic deformation (SPD) methods on production of ultra-fine grained (UFG) materials studied. Two main routes A and C investigated by FEM and compared with each other from different aspects of view. ABAQUS commercial software used to evaluate the maximum strain, maximum required force and strain inhomogeneity index in both routes and obtained results of FEM verified by both theoretical calculations and experimental tests. It is inferred that although equivalent plastic strain (PEEQ) in route A is higher than that in route C, the strain homogeneity as a quality factor for route C is higher. So, route C selected for more investigation and optimization. Grey relational analysis used as the optimization method. Geometrical parameters taken as input variables and both inhomogeneity index and maximum required load taken as objectives. Then, the suggested tests by full factorial method were simulated by FEM. After optimization, it was concluded that the best set up belongs to experiment number 20 which the values of Φ1, ψ1 and ψ2 are 165°, 0° and 15°, respectively. Also, it is inferred that among geometrical parameters, die channel angle (Φ1) is the most effective parameter.

[1] R.Z. Valiev, T.G. Langdon, "Principles of equal-channel angular pressing as a processing tool for grain refinement", Prog. Mater Sci., Vol. 51, No. 7, 2006, pp. 881-981.

[2] P. Bergwerf, "Equall channel angullar pressing of high carbon steel", Master Thesis, Delf University of Technology, Vol. No. 12 March 2007, pp.

[3] G. Faraji, M. Ebrahimi, A. Bushroa, "Ultrasonic assisted tubular channel angular pressing process", Mater. Sci. Eng., A, Vol. 599, No. 2014, pp. 10-15.

[4] M. Furukawa, Z. Horita, M. Nemoto, R.Z. Valiev, T.G. Langdon, "Microstructural characteristics of an ultrafine grain metal processed with equal-channel angular pressing", Mater. Charact., Vol. 37, No. 5, 1996, pp. 277-283.

[5] R. Jahadi, M. Sedighi, H. Jahed, "Ecap effect on the micro-structure and mechanical properties of am30 magnesium alloy", Mater. Sci. Eng., A, Vol. 593, No. 2014, pp. 178-184.

[6] S. Rusz, L. Cizek, M. Salajka, S. Tylsar, J. Kedron, V. Michenka, T. Donic, E. Hadasik, M. Klos, "Ultrafine grain refinement of almn1cu and az 31 alloys by spd process", Arch. Metall. Mater., Vol. 59, No. 1, 2014, pp. 359-364.

[7] V. Segal, "Materials processing by simple shear", Mater. Sci. Eng., A, Vol. 197, No. 2, 1995, pp. 157-164.

[8] Y. Yuan, A. Ma, J. Jiang, Y. Sun, F. Lu, L. Zhang, D. Song, "Mechanical properties and precipitate behavior of mg–9al–1zn alloy processed by equal-channel angular pressing and aging", J. Alloys Compd., Vol. 594, No. 2014, pp. 182-188.

[9] G. Deng, C. Lu, L. Su, A.K. Tieu, J. Li, M. Liu, H. Zhu, X. Liu, "Influence of outer corner angle (oca) on the plastic deformation and texture evolution in equal channel angular pressing", Comput. Mater. Sci, Vol. 81, No. 2014, pp. 79-88.

[10] H.S. Kim, M.H. Seo, S.I. Hong, "On the die corner gap formation in equal channel angular pressing", Mater. Sci. Eng., A, Vol. 291, No. 1, 2000, pp. 86-90.

[11] S. Li, X. Li, L. Yang, "Role of strain path change in grain refinement by severe plastic deformation: A case study of equal channel angular extrusion", Acta Mater., Vol. 61, No. 12, 2013, pp. 4398-4413.

[12] P. Prangnell, C. Harris, S. Roberts, "Finite element modelling of equal channel angular extrusion", Scr. Mater., Vol. 37, No. 7, 1997, pp. 983-989.

[13] F. Salimyanfard, M.R. Toroghinejad, F. Ashrafizadeh, M. Hoseini, J.A. Szpunar, "Investigation of texture and mechanical properties of copper processed by new route of equal channel angular pressing", Mater. Des., Vol. 44, No. 2013, pp. 374-381.

[14] S. Semiatin, D. Delo, E. Shell, "The effect of material properties and tooling design on deformation and fracture during equal channel angular extrusion", Acta Mate., Vol. 48, No. 8, 2000, pp. 1841-1851.

[15] S. Arab, A. Akbarzadeh, "The effect of equal channel angular pressing process on the microstructure of az31 mg alloy strip shaped specimens", J. Magnesium Alloys, Vol. 1, No. 2, 2013, pp. 145-149.

[16] J.Y. Park, D.N. Lee, "Deformation and annealing textures of equal-channel angular pressed 1050 al alloy strips", Mater. Sci. Eng., A, Vol. 497, No. 1, 2008, pp. 395-407.

[17] K. Nakashima, Z. Horita, M. Nemoto, T.G. Langdon, "Development of a multi-pass facility for equal-channel angular pressing to high total strains", Mater. Sci. Eng., A, Vol. 281, No. 1, 2000, pp. 82-87.

[18] H.S. Kim, "Finite element analysis of deformation behaviour of metals during equal channel multi-angular pressing", Mater. Sci. Eng., A, Vol. 328, No. 1, 2002, pp. 317-323.

[19] J. Jung, S.C. Yoon, H.-J. Jun, H.S. Kim, "Finite element analysis of deformation homogeneity during continuous and batch type equal channel angular pressing", J. Mater. Eng. Perform., Vol. 22, No. 11, 2013, pp. 3222-3227.

[20] G. Faraji, A. Babaei, M.M. Mashhadi, K. Abrinia, "Parallel tubular channel angular pressing (ptcap) as a new severe plastic deformation method for cylindrical tubes", Mater. Lett., Vol. 77, No. 2012, pp. 82-85.

[21] G. Faraji, M. Mousavi Mashhadia, "Plastic deformation analysis in parallel tubular channel angular pressing (ptcap)", J. Adv. Mater. Proc., Vol. 1, No. 4, 2013, pp. 23-32.

[22] G. Faraji, M. Mashhadi, K. Abrinia, H. Kim, "Deformation behavior in the tubular channel angular pressing (tcap) as a noble spd method for cylindrical tubes", Appl. Phys. A, Vol. 107, No. 4, 2012, pp. 819-827.

[23] G. Faraji, M. Mashhadi, A. Dizadji, M. Hamdi, "A numerical and experimental study on tubular channel angular pressing (tcap) process", J. Mech. Sci. Technol., Vol. 26, No. 11, 2012, pp. 3463-3468.

[24] G. Faraji, P. Yavari, S. Aghdamifar, M.M. Mashhadi, "Mechanical and microstructural properties of ultra-fine grained az91 magnesium alloy tubes processed via multi pass tubular channel angular pressing (tcap)", J. Mater. Sci. Technol., Vol. 30, No. 2, 2014, pp. 134-138.

[25] H.-j. Hu, D.-f. Zhang, F.-s. Pan, "Die structure optimization of equal channel angular extrusion for az31 magnesium alloy based on finite element method", Trans. Nonferrous Met. Soc. China, Vol. 20, No. 2, 2010, pp. 259-266.

[26] E. López-Chipres, E. García-Sanchez, E. Ortiz-Cuellar, M. Hernandez-Rodriguez, R. Colás, "Optimization of the severe plastic deformation processes for the grain refinement of al6060 alloy using 3d fem analysis", J. Mater. Eng. Perform., Vol. No. 2010, pp. 1-7.

[27] A. Nagasekhar, Y. Tick-Hon, "Optimal tool angles for equal channel angular extrusion of strain hardening materials by finite element analysis", Comput. Mater. Sci, Vol. 30, No. 3, 2004, pp. 489-495.

[28] T. Suo, Y. Li, Q. Deng, Y. Liu, "Optimal pressing route for continued equal channel angular pressing by finite element analysis", Mater. Sci. Eng., A, Vol. 466, No. 1, 2007, pp. 166-171.

[29] S. Xu, G. Zhao, X. Ma, G. Ren, "Finite element analysis and optimization of equal channel angular pressing for producing ultra-fine grained materials", J. Mater. Process. Technol., Vol. 184, No. 1, 2007, pp. 209-216.

[30] C. Wang, F. Li, H. Lu, Z. Yuan, B. Chen, "Optimization of structural parameters for elliptical cross-section spiral equal-channel extrusion dies based on grey theory", Chin. J. Aeronaut., Vol. 26, No. 1, 2013, pp. 209-216.

[31] F. Fereshteh-Saniee, M. Asgari, M. Barati, S.M. Pezeshki, "Effects of die geometry on non-equal channel lateral extrusion (necle) of az80 magnesium alloy", Trans. Nonferrous Met. Soc. China, Vol. 24, No. 10, 2014, pp. 3274-3284.

[32] A. Shokuhfar, O. Nejadseyfi, "The influence of friction on the processing of ultrafine-grained/nanostructured materials by equal-channel angular pressing", J. Mater. Eng. Perform., Vol. 23, No. 3, 2014, pp. 1038-1048.

[33] U. Çaydaş, A. Hasçalık, "Use of the grey relational analysis to determine optimum laser cutting parameters with multi-performance characteristics", Opt. Laser Technol., Vol. 40, No. 7, 2008, pp. 987-994.

[34] D.K. Panda, "Modelling and optimization of multiple process attributes of electrodischarge machining process by using a new hybrid approach of neuro–grey modeling", Mater. Manuf. Processes, Vol. 25, No. 6, 2010, pp. 450-461.

[35] S. Khalilpourazary, P. Kashtiban, N. Payam, "Optimization of turning operation of st37 steel using grey relational analysis", Vol. No. 2014, pp.

[36] C.-J. Tzeng, Y.-H. Lin, Y.-K. Yang, M.-C. Jeng, "Optimization of turning operations with multiple performance characteristics using the taguchi method and grey relational analysis", J. Mater. Process. Technol., Vol. 209, No. 6, 2009, pp. 2753-2759.

[37]K. Palanikumar, B. Latha, V. Senthilkumar, J.P. Davim, "Analysis on drilling of glass fiber–reinforced polymer (gfrp) composites using grey relational analysis", Mater. Manuf. Processes, Vol. 27, No. 3, 2012, pp. 297-305.

[38] J.A. Barrios, A. Cavazos, L. Leduc, J. Ramirez, "Fuzzy and fuzzy grey-box modelling for entry temperature prediction in a hot strip mill", Mater. Manuf. Processes, Vol. 26, No. 1, 2011, pp. 66-77.

[39] J. Kopac, P. Krajnik, "Robust design of flank milling parameters based on grey-taguchi method", J. Mater. Process. Technol., Vol. 191, No. 1, 2007, pp. 400-403.

[40] H. Lu, C. Chang, N. Hwang, C. Chung, "Grey relational analysis coupled with principal component analysis for optimization design of the cutting parameters in high-speed end milling", J. Mater. Process. Technol., Vol. 209, No. 8, 2009, pp. 3808-3817.

[41] L.K. Pan, C.C. Wang, S.L. Wei, H.F. Sher, "Optimizing multiple quality characteristics via taguchi method-based grey analysis", J. Mater. Process. Technol., Vol. 182, No. 1, 2007, pp. 107-116.

[42] Y. Iwahashi, Z. Horita, M. Nemoto, T.G. Langdon, "An investigation of microstructural evolution during equal-channel angular pressing", Acta Mater., Vol. 45, No. 11, 1997, pp. 4733-4741.

[43] N. El Mahallawy, F.A. Shehata, M.A. El Hameed, M.I.A. El Aal, H.S. Kim, "3d fem simulations for the homogeneity of plastic deformation in al–cu alloys during ecap", Mater. Sci. Eng., A, Vol. 527, No. 6, 2010, pp. 1404-1410.