A direct extrusion operation is performed on a cylindrical billet with an initial diameter of 2.0 in and an initial length of 4.0 in. The die angle = 60°, and the orifice diameter is 0.50 in. In the Johnson extrusion strain equation, a = 0.8 and b = 1.5. The operation is carried out hot, and the hot metal yields at 13,000 lb/in2 and does not strain harden when hot.
(a) What is the extrusion ratio?
(b) Determine the ram position at the point when the metal has been compressed into the cone of the die and starts to extrude through the die opening.
(c) What is the ram pressure corresponding to this position?
(d) Also determine the length of the final part if the ram stops its forward movement at the start of the die cone.