Influences of the geometrical conditions of die and workpiece on the barreling formation during forging–extrusion process

The main concern of this study is to investigate the material flow characteristics of solid cylinder upsetting with a hollow die subjected to different geometrical conditions such as taper angle and dimension of the aperture surface within the top die, and height-to-diameter ratio of the billet. During the forging–extrusion process, obviously two barrels, namely top barrel and bottom barrel, are successively formed along the lateral free surface of the workpiece, and an extrusion of the top free surface of the billet into the aperture surface within the top die is accompanied. A finite element-based methodology is utilized to examine the radii of the curvature of the barrels and the height of an extrusion of the top free surface into the aperture surface within the top die accordingly.