Copper alloy clad for coinage

• Main Authors: TYLER; DEREK E, BREEDIS; JOHN F
• Format: Patent
• Language: English
• Published: 05.12.1995
• Edition: 6
• Subjects: CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; SOLDERING OR UNSOLDERING; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TRANSPORTING; WELDING; WORKING BY LASER BEAM

There is provided a metallic composite useful for coinage. The core is formed from a copper alloy that contains between 50% and 99.0% copper, has a room temperature electrical conductivity in excess of 25% IACS an initial yield strength in excess of 10,000 psi and a dynamic softening response onset at a temperature in the range of 200 DEG C.-400 DEG C. The cladding layers have an initial yield strength more than that of the core and a gold color. The strengthening response of the core during cladding is similar to that of the cladding layers making the metallic composites resistant to corrugation. Reducing corrugation increases the sensitivity of electromagnetic coin discriminators.