2004 年 54 巻 4 号 p. 148-152
In order to reduce the change of the flow velocity between the initial stage and the end stage of the aluminum extrusion process, the die structure were investigated by the extrusion experiments and finite-element method (FEM) simulation. As a result, it was confirmed that the change in the flow velocity reduced by setting the ring between a die and a container, and there were the most suitable dimensions of the ring, which became the smallest change in the flow velocity ratio. Furthermore, the change in the cross sectional dimension of the profile extruded from the die with this ring was the smallest.