A comparison between numerical and analytical modeling of ECAP

Document Type: Research Paper


1 Khajenasir University of Technology

2 K.N. Toosi University of Technology


Recent developments in nanostructured products draw considerable attention to ultrafine grained materials. These materials are normally manufactured by different severe plastic deformation (SPD) methods. In the present study, analytical models and finite element method (FEM) are used to calculate strain imposed to a specimen that was deformed by equal channel angular pressing (ECAP). In addition, strain inhomogeneity in term of coefficient of deviation (CV) for an aluminum alloy (AA6101) processed under ECAP was calculated. Dies with 90º, 105º and 120º intersecting angles were modeled based on FEM. Furthermore, the effect of friction on force-displacement curves was investigated using analytical and numerical approaches. Moreover, the energy loss that is due to friction was computed. Strains calculated by FEM for different die angles were identical to those evaluated by analytical models. Based on numerical and analytical models, it has been shown that strain inhomogeneity increases when the angle between two channels decreases.


[1] K. Narooei, A. Karimi Taheri, A new model for prediction the strain field and extrusion pressure in ECAE process of circular cross section, Applied Mathematical Modelling, 34 (2010) 1901-1917.

[2] V. Segal, Slip line solutions, deformation mode and loading history during equal channel angular extrusion, Materials Science and Engineering: A, 345 (2003) 36-46.

[3] M. Reihanian, R. Ebrahimi, M. Moshksar, Upper-bound analysis of equal channel angular extrusion using linear and rotational velocity fields, Materials & Design, 30 (2009) 28-34.

[4] B. Altan, G. Purcek, I. Miskioglu, An upper-bound analysis for equal-channel angular extrusion, Journal of materials processing technology, 168 (2005) 137-146.

[5] M. Paydar, M. Reihanian, R. Ebrahimi, T. Dean, M. Moshksar, An upper-bound approach for equal channel angular extrusion with circular cross-section, Journal of materials processing technology, 198 (2008) 48-53.

[6] C. Luis Pérez, R. Luri, Study of the ECAE process by the upper bound method considering the correct die design, Mechanics of Materials, 40 (2008) 617-628.


[7] A. Nagasekhar, S. Yoon, Y. Tick-Hon, H. Kim, An experimental verification of the finite element modelling of equal channel angular pressing, Computational Materials Science, 46 (2009) 347-351.

[8] V. Patil Basavaraj, U. Chakkingal, T. Prasanna Kumar, Study of channel angle influence on material flow and strain inhomogeneity in equal channel angular pressing using 3D finite element simulation, Journal of materials processing technology, 209 (2009) 89-95.

[9] D. Nagarajan, 2005. Processing of an aluminium alloy by ECAE, p.t.c.e.M.S.T.I.I. of, p. Technology Madras.


[10] 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, 35 (1996) 143-146.

[11] R. Z. Valiev, T. G. Langdon, Principles of equal-channel angular pressing as a processing tool for grain refinement, Progress in Materials Science, 51 (2006) 881-981.