FEA analysis during extrusion of polygonal sections from round billet through linearly converging dies using SERR Technique

The extrusion of section from round billet poses a great challenge for theoretical modeling of the process using upper bound method. The greatest difficulty in three-dimensional upper bound method is to determine kinematically admissible velocity field. The SERR (Spatial Elementary Rigid Region) technique is fairly applicable for analyzing extrusion of sections having re-entrant corners. A modified version of SERR technique has been used for extrusion of hexagon sections from round billet through a linearly converging die. The circular cross section of the round billet is approximated by a regular polygon of equal area. The extrusion pressure has been computed for different boundary condition at the die billet interface. The optimum die geometry has been determined. An extrusion test rig is designed and all extrusion is carried out using round billets for extrusion of hexagonal sections using converging dies. The experimental results are validated with SERR analysis.