This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Determination of Geometrical Parameters of the Dead Metal Zone and Exit Curvature Profile in the Extrusion Process of Non-Symmetrical Flat Dies
Technical Paper
2012-01-0052
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
To determine the curvature of the exit profile in the extrusion process of non-symmetrical flat dies, the dead metal zone profile was predicted using the energy minimization method. The dead zone is a natural non-linear die for the process and it is pragmatic to use this non-linear die to estimate the value of the exit profile curvature and the required bearing length for reducing this deviation. The velocity field is calculated based on Hermite cubic spline and some additional assumptions. In non-symmetrical dies the entrance section of the deformation region is not flat. Considering this fact, axial velocity decreases with increasing the distance to die center line which is in agreement with experiment. After determination of the velocity field, the strain rates in different directions are calculated. Subsequently, the required power for the process is estimated using the upper bound method. Since the material tends to consume less energy, to determine the profile of the dead zone, the coefficients of the curve are set so as to minimize the consumed power. Finally, using this curve, the value of the exit profile curvature is estimated. Dead metal zone for different angles of the deformation region at entry and different friction constant coefficients was determined and compared with the results of simulations of the finite element software (ABAQUS v6.9). Additionally, the deviation calculated from theoretical method was verified with the results of the commercially available bulk forming simulation software (Deform-3D v5). This method does not depend on the exit section and is applicable to non-symmetrical dies as well. The analytical results for non-symmetrical T-die are in good agreement with results of the finite element simulations.
Recommended Content
Authors
Topic
Citation
Rastegar, M., Assempour, A., and Ghazanfari, A., "Determination of Geometrical Parameters of the Dead Metal Zone and Exit Curvature Profile in the Extrusion Process of Non-Symmetrical Flat Dies," SAE Technical Paper 2012-01-0052, 2012, https://doi.org/10.4271/2012-01-0052.Also In
References
- Alexandrov, S. Mishuris, G. Miszuris, W. Sliwa, R.E. “On the dead zone formation and limit analysis in axially symmetric extrusion,” Int. J. Mech. Sci. 43 367 379 2001
- Takuda, H. Hatta, N. “A Simple Approach to Plan Strain Extrusion with dead Metal Zone Using Upper-bound Theorem,” Met. Mat 4 4 737 741 1998
- Qamar, S.Z. “FEM study of extrusion complexity and dead metal zone” Arch. Mat. Sci. Eng. 36 2 110 117 2009
- Chitkara, N. R. Abrinia, K. “A Generalized Upper-bound Solution for Three Dimensional Extrusion of Shaped Sections using CAD/CAM Bilinear Surface Dies,” MACH. DES-CON 28 USA 1990
- Chitkara, N. R. Celik, K. F. “A Generalized CAD/CAM Solution to the Three Dimensional Off-centeric Extrusion of Shaped Section: Analysis,” Int. J. Mech. Sci. 42 273 294 2000
- Yang, D.Y. Kim, M.U. Lee, C.H. “An Analysis for Extrusion of Helical Shapes from Round Billets,” Int. J. Mech. Sci. 20 695 705 1978
- Assempour, A. Hasannejadasl, A. “Minimization of the exit profile curvature in non-symmetric T-shaped sections in the extrusion process,” Int. J. Mat. Des. 30 1350 1355 2009
- Khalili Meybodi, A. Assempour, A. Farahani, S. “A general methodology for bearing design in non-symmetric T-shaped sections in extrusion process,” J. Mat. Pro. Tech. 212 249 261 2012
- Sluzalec, A. “An Analysis of dead zone in the process of direct extrusion through single-hole flat die,” Int. J. Com. App. Num. 7 281 287 1991