STUDY OF METAL FLOW IN EXTRUSION FORGING OF RECTANGULAR BILLETS

The deformation of a rectangular billet between a grooved die and a fl at die takes place in an extrusion-forging mode in which the billet ma terial is forced simultaneously into the die orifice and the flash gap . This mode of deformation is similar to the initial stages of the clo sed-die forging process, the understanding of such deformation process being important for both product quality control and forming tool des ign. In this paper, the metal flow behaviour during the extrusion forg ing of a rectangular billet between a grooved die and a flat die has b een studied using the finite-element method with a view to extending t he application to more complicated practical cases. The emphasis has b een on the deformed profiles rather than on the forging load. Experime nts using two sets of dies with different parameters and lead billets were performed, good agreement being found between the experimental an d numerical results in terms of the deformed profiles.