CONTINUOUS EXTRUSION BY THE CONFORM PROCESS.

A new method for the continuous extrusion forming of metals developed at the United Kingtom Atomic Energy Authority (UKAEA) Reactor Fuel Element Laboratories, Springfields and first introduced by them three years ago is now beginning to have some commercial impact. In conventional direct extrusion, because of the friction which exists between the billet and the container, the force required to commence extrusion limits the length of billets to about 5 times their diameter. In the Conform process however, this friction is used to advantage. The conventional cylindrical container is replaced by a split container of rectangular cross section. The upper part has a rectangular section groove into which is loaded a tightly fitting rectangular billet and the lower part holds the die piece which blocks one end of the groove. If the upper part of the container is moved toward the die the friction between the billet and the three sides of the groove will act to push the billet against the die. Likewise the friction between the billet and the top surface of the lower part of the container will act to oppose forward motion. The net force, equivalent to the friction between the billet and two sides of the groove will be directed to driving the billet against the die. It has been determined by calculation and confirm in practice that the length of container required to create sufficient pressure to cause extrusion of copper and aluminum and their alloys is easily attainable.