An Experimental Study of Axially Symmetric Inverted Extrusion and Piercing

Two metal-forming processes - axially symmetric inverted extrusion with square dies, and axially symmetric piercing with fiat punches - are considered. Experiments were performed with 0.06 per cent tellurium lead, both in an initially work-hardened state and in an initially annealed state. The relationships between die pressure and reduction which were obtained for the two processes are compared, and an attempt is made to correlate the die pressures with the stress-strain curves for the metal.The results obtained indicate that axially symmetric piercing with a fiat punch is more efficient than axially symmetric extrusion with square dies.