Development of Piercing Punch for High Durability and Product Quality in Laminate Shearing of Amorphous Alloy Foil

Abstract

The conventional shearing of amorphous alloy foil induced significant damage in them because of their high strength and low ductility. New shearing tools with a tailored chamfer at the punch cutting edge were proposed. The chamfer size was varied to describe its effect on the shearing behavior. Without chamfers, chipping occurred at the punch cutting edge after only 100 shots. No chipping was observed even after 1000 shots when using the chamfered punch, irrespective of the chamfer size. In particular, when the chamfer size was reduced to 10 μm, no chipping occurred, and the punch cutting edge was only slightly worn even after 50,000 repetitions of piercing the five-laminate amorphous alloy foil stack. This well-conditioned punch cutting edge resulted in the formation of high-quality pierced holes.