Patent ID: 11946129

Abstract:
To provide, as a sheet material of a Cu—Ni—Al based copper alloy having a compositional range exhibiting a whitish metallic appearance that is excellent in “strength-bending workability balance” and is excellent in discoloration resistance, 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 Ni/Al≤15.0, and having a metallic structure having, on an observation plane in parallel to a sheet surface (rolled surface), a number density of fine secondary phase particles having a particle diameter of 20 to 100 nm of 1.0×107 per mm2 or more.