Cold Piercing of Cylindrical Aluminum Billet with Counter Punch Pressure

Abstract:

To make a hole with a high aspect ratio (depth/diameter) for lightweight structural components, piercing of cylindrical billet of aluminum alloy was carried out against a counter pressure on a servo-controlled double axis press. To obtain smooth shear surface of pierced hole, the counter pressure was applied to the billet by a counter punch from the opposite side of a piercing punch during piercing. Irrespective of amount of clearance of die–piercing punch, ratio of the length of shear surface/depth of pierced hole in the pierced billet reached about 0.9 by applying a counter punch pressure of 0.2 GPa. The maximum aspect ratio of the hole in the proposed piercing method was estimated to be approximately of 15 for the aluminum billet from viewpoints of buckling and strength of the punch.

• Periodical: Key Engineering Materials (Volumes 554-557)
• Pages: 613-619
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.554-557.613
• Online since: June 2013
• Authors: Ryo Matsumoto, Hiroshi Utsunomiya
• Keywords: Forging, Lightweight Structure, Piercing, Servo Press

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