Aluminum clad zinc bimetallic coin planchet

摘要

A composite metal laminate coin planchet comprises commercially pure aluminum cladding layers metallurgically bonded to a zinc alloy core. The zinc alloy core may contain a hardening agent, such as copper or titanium, used to increase the hardness of the alloy above that of pure zinc. Trace amounts of other elements may also be present in the zinc alloy core or in the commercially pure aluminum cladding layers which do not affect their pertinent properties. The coin planchet is produced by a process comprising providing a strip or sheet of a zinc alloy core and creating a strip or sheet of composite material by metallurgically bonding commercially pure aluminum cladding layers to the zinc alloy. The coin planchets are then removed from the strip or sheet of composite material, and the remaining composite material is heated above its melting point to produce a zinc-aluminum alloy useful in die-casting.