| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-strength copper alloy material that has not only such strength, electroconductivity, bendability and solder wettability as to be suitable for electrical/electronic parts such as a connector, a relay, a switch, a socket and a lead frame, but also improved stress corrosion cracking resistance. SOLUTION: The copper alloy has a composition comprises, by mass%, 0.4-4.5% Ni, 0.15-0.9% Si, 5-15% Zn, further one or more elements of 2.0% or less Sn, 0.2% or less P, 1.0% or less Fe, 0.5% or less Mg, 4.0% or less Co and 4.0% or less Cr, as needed, and the balance substantially Cu. Also, the copper alloy has a Si solid-solution index (Z) of 0.55 to 0.9, which is calculated from the electroconductivity and the composition, a tensile strength of 650 N/mm<SP>2</SP>or higher, and preferably the electroconductivity of 25% IACS or higher. COPYRIGHT: (C)2007,JPO&INPIT
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