Numerical Analysis on the Extruded Volume and Length Ratios of Backward Tube to Forward Rod in Combined Extrusion Processes


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This paper is concerned with forward rod extrusion combined simultaneously with backward tube extrusion process in both steady and transient states. The analysis has been conducted in numerical manner by employing a rigid-plastic finite element method. AA 2024 aluminum alloy was selected as a model material for analysis. Among many process parameters, major design factors chosen for analysis include frictional condition, thickness of tube in backward direction, punch corner radius, and die corner radius. The main goal of this study is to investigate the material flow characteristics in combined extrusion process, i.e. forward rod extrusion combined simultaneously with backward tube extrusion process. Simulation results have been summarized in term of relationships between process parameters and extruded length and volume ratios, and between process parameters and force requirements, respectively. The extruded length ratio is defined as the ratio of tube length extruded in backward direction to rod length extruded in forward direction, and the volume ratio as that of extruded volume in backward direction to that in forward direction, respectively. It has been revealed from the simulation results that material flow into both backward and forward directions are mostly influenced by the backward tube thickness, and other process parameters such as die corner radius etc. have little influence on the volume ratio particularly in steady state of combined extrusion process. The pressure distributions along the tool-workpiece interface have been also analyzed such that the pressure exerted on die is not so significant in this particular process such as combined operation process. Comparisons between multi-stage forming process in sequence operation and one stage combined operation have been also made in terms of forming load and pressure exerted on die. The simulation results shows that the combined extrusion process has the greatest advantage of lower forming load comparing to that in sequence operation.



Materials Science Forum (Volumes 519-521)

Edited by:

W.J. Poole, M.A. Wells and D.J. Lloyd






B.S. Ham et al., "Numerical Analysis on the Extruded Volume and Length Ratios of Backward Tube to Forward Rod in Combined Extrusion Processes", Materials Science Forum, Vols. 519-521, pp. 919-924, 2006

Online since:

July 2006




[1] W. Osen: Proceedings of the 2nd International Conference on the Technology of Plasticity (Stuttgart, 1987), p.575.

[2] J. A. Paul, R. Shivpuri and T. Altan: Development of equipment and capabilities for investigation of multi-action forming of complex parts (ERC/NSM Report, No. B8928 1989), p.11.

[3] H. H. Lin, K. Kawakami and H. Kudo: Ann. CIRP Vol. 37 (1988), p.231.

[4] H. H. Lin and H. Kudo: Proceedings of the fourth ICTP (Beijing, China, 1993), p.1239.

[5] K. Osakada, X. Wang and S. Hanami: J. Mater. Process. Technol. Vol. 71 (1997), p.105.

[6] K. Kuzman: Proceedings of the Sixth ICTP (Nuremberg, Germany, 1999), p.805.

[7] S.I. Oh, G.D. Lahoi, T. Altan: ALPID-a General Purpose FEM Program for Metal Forming (Proc. of NAMRC. IX, State college, Pennsylvania 1981).

[8] Int. Cold Forging Group: General recommendations for design, manufacture and operational aspects of cold extrusion tools for steel components (ICFG Doc. No 6/82, Portcullis Press 1983).

[9] J.A. Schey: Metal Deformation Processes Friction and Lubrication (Marcel Dekker, New York 1970).

[10] Air Force Material Laboratory: Forming equipment, materials and practices (Metal and Ceramics Information Center 1973), p.164.

[11] T. Huziyoshi: Die and Moulding (Daily Technology Press, Tokyo, Japan 1989).

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