To produce a copper alloy having simultaneously various characteristics (that is excellent in strength, electric conductivity, Youung's modulus, press formability, cost or the like) required for the material for electrical and electronic parts such as a connector, and to provide its producing method.
The copper alloy material having a composition containing Ni, P, Zn and Sn in the ranges of, by weight, 20 to 41% Zn, 0.1 to 4.0% Sn, 0.1 to 5.0% Ni and 0.01 to 0.3% P also so as to satisfy the following inequalities of 5.0≤Ni/P≤50; wherein Ni: the content (wt.%) of Ni, and P: the content (wt.%) of P and 6.0≤0.25X+Y≤12; wherein X: the content (wt.%) of Zn, and Y: the content (wt.%) of Sn, and the balance Cu with inevitable impurities is heat-treated at 300 to 750°C for 1 to 360 min, then cold-worked at a working ratio of ≥10% and heat-treated at 200 to 600°C for 5 sec to 180 min. Thus the objective copper whose tensile strength in the rolling direction is ≥600 N/mm2, electric conductivity is ≥18% IACS, Young's modulus is ≤120 kN/mm2 and spring critical value is ≥450N/mm2 can be produced.
RYO RAKU
SUGAWARA AKIRA
