CPC C22F 1/08 (2013.01) [C22C 9/06 (2013.01)] | 7 Claims |
1. A copper alloy sheet material having a composition containing, in terms of % by mass, Ni: more than 12.0% and 30.0% or less, Al: 1.80-6.50%, Mg: 0-0.30%, Cr: 0-0.20%, Co: 0-0.30%, P: 0-0.10%, B: 0-0.05%, Mn: 0-0.20%, Sn: 0-0.40%, Ti: 0-0.50%, Zr: 0-0.20%, Si: 0-0.50%, Fe: 0-0.30%, and Zn: 0-1.00%, with the balance of Cu and unavoidable impurities, and satisfying the following expression (1), and
having a metallic structure having, on an observation plane in parallel to a sheet surface, a number density of fine secondary phase particles having a particle diameter DM defined by the following (A) of 20 to 100 nm of 1.0×107 per mm2 or more:
Ni/Al≤15.0 (1)
wherein in the expression (1), the atomic symbols are substituted by the contents of the elements expressed with % by mass,
(A) assuming that for one secondary phase particle, a diameter (nm) of a minimum circle surrounding the particle is referred to as a “major diameter”, and a diameter (nm) of a maximum circle encompassed in a contour of the particle is referred to as a “minor diameter”, a value shown by (major diameter+minor diameter)/2 is designated as the particle diameter DM of the particle.
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