In cold combined forward-backward extrusion, a method employing an axially driven tapered container is proposed to obtain a product with arbitrary extrusion lengths under a possible least forming pressure. In this method, the container, which is tapered in one side, is moved in the axial direction using an actuator while the billet material is extruded in two directions by the punch. The material flow in the direction of the container movement is promoted and the flow in the opposed one is restricted not only by the effect of the friction over the container-billet interface but also by the effect of the axial tension given through the tapered part of the container. Thus, the material flow in the two directions can be controlled by changing the container speed, the angle of the taper and the initial position of the tapered container. The effectiveness of the proposed method is examined by experiments using a model material (plasticine) and by FEM simulation. The results show that the material flow in the two directions of extrusion can be controlled to a great extent.
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