A New Low Friction Die Design for Equal Channel Angular Extrusion

The paper presents the experimental results on an aluminum alloy and a silver alloy processed by equal channel angular extrusion in order to refine the grains. Two type of extrusion dies have been used for experimental works: one with fixed walls and the other one with movable walls in order to reduce the friction during extrusion process. The new concept of the die consists in simultaneously pressing of two samples in one entering channel with two opposite exit channels. The channel geometry, friction contact, strain rate, extrusion load and micro structure aspects are presented.