Experimental and numerical study of optimum die profile in backward rod extrusion

The aim of this research is the reduction in deformation load in backward rod extrusion by means of an optimum die profile. In this respect, the stress and load relations in this process have been obtained by the incremental slab method for a curved die profile. By the use of a computer program, the optimum die profile has been obtained on the basis of minimisation of stress and load in die-workpiece contact surface. By using the FEM software, ABAQUS, the optimum die angle for the conical die in the same conditions is also determined. Then, the finite-element and experimental load–displacement curves have been determined. It is illustrated that the extrusion load for optimum curved die is reduced by 11%, compared to that in the optimum conical die.