FEM simulation of aluminium extrusion through two-hole multi-step pocket dies

Multi-hole pocket dies are a type of extrusion tooling setup commonly used across the aluminium extrusion industry for efficient production of solid aluminium profiles. Such dies are designed on the basis of experience and corrected after a number of trial extrusion runs before becoming usable. Computer simulation based on the finite element method (FEM) is in principle capable of predicting metal flow through the dies designed, but it is yet a huge technological challenge to simulate the extrusion process to produce profiles of industrial significance. The present research was attempted to investigate the effect of steps in the die pocket on metal flow to produce two chevron profiles with unequal thicknesses through two-hole dies, by means of 3D FEM simulation of extrusion in the transient state. The results showed that the pocket step could be effectively used to balance metal flow. Extrusion experiments validated the predictions of metal flow, extrudate temperature and the pressure required for extrusion through the pocket dies with three different designs. 3D FEM was demonstrated to be a powerful tool in optimising die design and decreasing the number of trial extrusion runs.

[1]  L. Tomesani,et al.  Advances on Extrusion Technology and Simulation of Light Alloys , 2008, Key Engineering Materials.

[2]  L. Tong.  FE simulation of bulk forming processes with a mixed eulerian-langrangian formulation , 1995 .

[3]  Jie Zhou,et al.  Prediction of temperature evolution during the extrusion of 7075 aluminium alloy at various ram speeds by means of 3D FEM simulation , 2004 .

[4]  P. B. Mellor,et al.  Extrusion through single hole staggered and unequal multi-hole dies , 1958 .

[5]  W. Johnson,et al.  On the multiple hole extrusion of sheets of equal thickness , 1957 .

[6]  Hans Keife.  Extrusion through two die openings: A 2D upper-bound analysis checked by plasticine experiments , 1993 .

[7]  I. Flitta,et al.  Nature of friction in extrusion process and its effect on material flow , 2003 .

[8]  Robert E. Johnson,et al.  A study of the effect of the process variables in unsymmetrical single-hole and multi-hole extrusion processes , 1998 .

[9]  Jie Zhou,et al.  3D FEM simulation of the whole cycle of aluminium extrusion throughout the transient state and the steady state using the updated Lagrangian approach , 2003 .

[10]  Mark Jolly,et al.  Finite element modelling investigations upon the influence of pocket die designs on metal flow in aluminium extrusion: Part II. Effect of pocket geometry configurations on metal flow , 2003 .

[11]  F. Parvizian,et al.  Application of Adaptive Mesh and ALE Method in Simulation of Extrusion of Aluminum Alloys , 2008 .

[12]  T. Sheppard,et al.  Effect of die pockets on multi-hole die extrusion , 2005 .

[13]  Terry Sheppard,et al.  Material flow during the extrusion of simple and complex cross-sections using FEM , 2005 .

[14]  Terry Sheppard,et al.  Simulation of multi-hole die extrusion , 2004 .

[15]  W. Johnson,et al.  The cold extrusion of circular rods through square multiple hole dies , 1957 .