| 摘要 |
PROBLEM TO BE SOLVED: To provide a copper alloy for electronic and electrical apparatuses which has excellent proof strength-flexure balance, is especially excellent in stress relaxation resistance characteristics, and is suitable for parts for electronic and electrical apparatuses, including terminals of e.g. connectors, relays, and lead frames.SOLUTION: A copper alloy for electronic and electrical apparatuses contains 1.0-5.0 mass% of Ni, 0.1-1.5 mass% of Si and the remaining mass being Cu and unavoidable impurities, and has a composition where a Ni/Si mass ratio falls in a range of 2.0-6.0. A special particle boundary length ratio, (L&sgr;/L), or a ratio of the sum L&sgr; of individual particle boundary lengths of &Sgr;3, &Sgr;9, &Sgr;27a and &Sgr;27b to all the crystal particle boundary lengths, is 30% or higher, and a ratio R{200} of X-ray diffraction intensity from a {200} plane on a surface of a material is 0.2 or higher. |
