| 摘要 |
PROBLEM TO BE SOLVED: To provide a gold copper base alloy useful as the one for a coin and to provide a copper base alloy having electric characteristics same as those of a C713 copper alloy and having discoloration resistance suitable for maintaining the appearance of the gold over a long period. SOLUTION: This copper base alloy substantially has a compsn. contg., by weight, 10 to 15% zinc, 7 to 12% manganese and 2 to 6% nickel, and the balance copper with inevitable impurities and has the electric conductivity of 5 to 7% IACS. The alloy has the electric conductivity in the cross-sectional direction substantially equal to that of a C713 copper alloy. In the case a cladding material is formed by bring clad to a C110 copper alloy, it has the electric conductivity substantially equal to that of one U.S. dollar coin designed with Susan B Ansony. |
