Simulation of metal flow in billets during extrusion by plasticine

Abstract

Billets of plasticine were extruded to the round rods, and the flow patterns were observed. Billets were made of black rods of plasticine which were alternatively wound by the black and white plates of plasticine. Flow patterns were observed which were produced by the four types of methods combined the rough and smooth surface conditions of the container and die, respectively. No dead metal zone was observed only when the surfaces of the die and container were smooth. Little difference was observed in the shape of the dead metal zones obtained at the different extrusion ratio, except the case near the die exit. The outside skin of the billet was extruded at the final stage. When the inner surface of the container was rough, the outside skin did not appear on the surface of the products. On the contrary, when the inner surface of the container was smooth the surface skin of billet flowed to the surface of the products over the surface of the dead metal zone. When the surface of the dummy block was rough the piping did not appear until the discard thickness reduced. The large die exit produced the large piping. The inside diameter of the piping slightly decreased with the decrease in the discard thickness.