| 摘要 |
A copper alloy according to the present invention includes 17 mass% to 34 mass% of Zn, 0.02 mass% to 2.0 mass% of Sn, 1.5 mass% to 5 mass% of Ni, and a balance consisting of Cu and unavoidable impurities, in which relationships of 12‰¤f1=[Zn]+5×[Sn]-2×[Ni]‰¤30, 10‰¤[Zn]-0.3×[Sn]-2×[Ni]‰¤28, 10‰¤f3={f1×(32-f1)×[Ni]} 1/2 ‰¤33, 1.2‰¤0.7×[Ni]+[Sn]‰¤4, and 1.4‰¤[Ni]/[Sn]‰¤90 are satisfied, conductivity is 13% IACS to 25% IACS, a ratio of an ± phase is 99.5% or more by area ratio or an area ratio of a ³ phase (³)% and an area ratio of a ² phase (²)% in an ± phase matrix satisfy a relationship of 0‰¤2×(³)+(²)‰¤0.7. |
