Numerical Investigation of Plastic Deformation in Two-turn Equal Channel Angular Extrusion
There has been a number of investigations in recent years reporting on the structure and properties of materials deformed to super plastic deformation (SPD). During SPD new textures can be formed and abnormal characteristics are displayed, attracting a growing research interest.¶ Equal channel angular extrusion (ECAE) is a method often used to obtain large plastic strains. However, according to experimental results, there is a large tensile stress in the sample during deformation, which may lead in some cases, to cracking in metallic alloys and large curvature in polymeric materials. In order to overcome these drawbacks, the ECAE process can be conducted at high temperatures. But this contributes significantly to a decreased level of plastic deformation induced in the sample. Hence, a tool with multi-pass seems to be a very appropriate solution. In this paper, a new geometry die composed of two elbows has been simulated by finite element method aiming to provide an insight into the mechanisms of deformation and to determine the optimum geometry of the tool. The numerical results show that the length and the section of the second channel play a significant role on the homogeneity of the plastic strain distribution. It has been found that good homogeneity was obtained when the second channel has the same section as that of the entrance and the exit channels and with a length equal to three times of its width.
Keywords:ECAE, finite element modelling, equivalent plastic strain, friction
V. M. Segal, “Materials processing by simple shear”, Materials Science and Engineering:A, Vol. 197, No. 2, pp. 157-164, 1995 DOI: https://doi.org/10.1016/0921-5093(95)09705-8
Y. Iwahashi, J. Wang, Z. Horita, M. Nemoto, T. G. Langdon, “Principle of equal-channel angular pressing for the processing of ultra-fine grained materials ”, Scripta Materialia, Vol. 35, No. 2, pp.143-146, 1996 DOI: https://doi.org/10.1016/1359-6462(96)00107-8
S. L. Semiatin, D. P. Delo, E. B. Shell, “The effect of material properties and tooling design on deformation and fracture during equal channel angular extrusion”, Acta Materialia, Vol. 48, No. 8, pp. 1841-1851, 2000 DOI: https://doi.org/10.1016/S1359-6454(00)00019-7
P. N. Fagin, J. O. Brown, T. M. Brown, K. V. Jata, S. L. Semiatin, “Failure modes during equal channel angular extrusion of aluminum alloy 2024”, Metallurgical and Materials Transactions A, Vol. 32, No. 7, pp. 1869-1871, 2001 DOI: https://doi.org/10.1007/s11661-001-0165-z
R. B. Figueiredo, P. R. Cetlin, T. G. Langdon, “The evolution of damage in perfect-plastic and strain hardening materials processed by equal-channel angular pressing”, Materials Science and Engineering: A, Vol. 518, No. 1-2, pp. 124-131, 2009 DOI: https://doi.org/10.1016/j.msea.2009.04.007
C. K. Y. Li, Z. Y. Xia, H. J. Sue, “Simple shear plastic deformation behaviour of polycarbonate plate. II: Mechanical property characterization”, Polymer, Vol. 41, No. 16, pp. 6285-6293, 2000 DOI: https://doi.org/10.1016/S0032-3861(99)00837-X
H. J. Sue, H. Dilan, C. K. Y. Li, “Simple shear plastic deformation behavior of polycarbonate plate due to the equal channel angular extrusion process. I: Finite element methods modeling”, Polymer Engineering and Science, Vol. 39, No. 2, pp. 2505-2515, 1999 DOI: https://doi.org/10.1002/pen.11638
F. Zairi, B. Aour, J. M. Gloaguen, M. Nait-Abdelaziz, J. M. Lefebvre, “Influence of the initial yield strain magnitude on the materials flow in equal-channel angular extrusion process”, Scripta Materialia, Vol. 56, No. 2, pp. 105-108 DOI: https://doi.org/10.1016/j.scriptamat.2006.09.032
B. Aour, F. Zairi, M. Nait-Abdelaziz, J. M. Gloaguen, J. M. Lefebvre, “Analysis of polypropylene deformation in a 135° ECAE die: experiments and three-dimensional finite element simulations”, Key Engineering Material, Vol. 424, pp. 71-78, 2010 DOI: https://doi.org/10.4028/www.scientific.net/KEM.424.71
J. Alkorta, J. G. Sevillano, “A comparison of FEM and upper-bound type analysis of equal-channel angular pressing (ECAP)”, Journal of Material Processing and Technology, Vol. 141, No. 3, pp. 313-318, 2003 DOI: https://doi.org/10.1016/S0924-0136(03)00282-6
I. J. Beyerlein, C. N. Tome, “Analytical modelling of material flow in equal channel angular extrusion (ECAE)”, Materials Science and Engineering: A, Vol. 380, No. 1-2, pp. 171-190, 2004 DOI: https://doi.org/10.1016/j.msea.2004.03.063
C. J. Luis Perez, R. Luri, “Upper Bound Analysis of the ECAE Process by Considering Circular Cross-Section and Strain Hardening Materials”, Journal of Manufacturing Science and Engineering, Vol. 132, No. 4, Art. No. 041003, 2010 DOI: https://doi.org/10.1115/1.4001550
B. Aour, F. Zairi, J. M. Gloaguen, M. Nait-Abdelaziz, J. M. Lefebvre, “Numerical investigation on equal channel angular extrusion process of polymers”, Computational Materials Science, Vol. 37, No. 4, pp. 491-506, 2006 DOI: https://doi.org/10.1016/j.commatsci.2005.11.008
B. Aour, F. Zairi, M. Nait-Abdelaziz, J. M. Gloaguen, O. Rahmani, J. M. Lefebvre, “A computational study of die geometry and processing conditions effects on equal channel angular extrusion of a polymer”, International Journal of Mechanical Sciences, Vol. 50, No. 3, pp. 589-602, 2008 DOI: https://doi.org/10.1016/j.ijmecsci.2007.07.012
B. Aour, F. Zairi, J. M. Gloaguen, M. Nait-Abdelaziz, J.M. Lefebvre, “Finite element analysis of plastic strain distribution in multi-pass ECAE process of high density polyethylene”, Journal of Manufacturing Science and Engineering,Vol. 131, No. 3, Art. No. 031016 , 2009 DOI: https://doi.org/10.1115/1.3139217
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