Combined extrusion processes generally have advantages of forming in terms of the
minimum deformation power since the material is pressed through two or more orifices
simultaneously. This paper is concerned with the analysis of forming load characteristics of a
forward-backward can extrusion process using thick-walled pipe as an initial billet. The combined
tube extrusion process was analyzed by using a commercial finite element code. A thick-walled pipe
was selected as an initial billet and the punch geometry has been chosen on the basis of ICFG
recommendation. Several tool and process parameters were employed in this analysis and they are
punch nose radius, backward tube thickness, punch face angle, and frictional conditions, respectively.
The main purpose of this study is to investigate the effect of process parameters on the force
requirements in combined extrusion process. The possible extrusion process to form a
forward-backward tube parts in different process sequences were also simulated to investigate the
force requirements in sequential operations, i.e. separate operations. It was easily concluded from the
simulation results that lower forming load was predicted for the combined extrusion, compared to
those for separate sequential operations. It was also revealed that the punch nose radius and the punch
face angle have little effect on the force requirements and the forming load increases significantly as
the frictional condition along tool-workpiece interface becomes severe. The simulation results in this
study suggest that the combined extrusion process has strong advantage in terms of force
requirements as long as the simultaneous material flow into multiple orifices could be closely
controlled.
Effect of Process Parameters on Purification of Aluminium Alloys by Backward Extrusion Process under a Semisolid Condition
