High strength cu—ni—co—si based copper alloy sheet material and method for producing the same, and current carrying component

Abstract

A copper alloy sheet material comprises (by mass %) from 2.50 to 4.00% in total of Ni and Co, from 0.50 to 2.00% of Co, from 0.70 to 1.50% of Si, from 0 to 0.50% of Fe, from 0 to 0.10% of Mg, from 0 to 0.50% of Sn, from 0 to 0.15% of Zn, from 0 to 0.07% of B, from 0 to 0.10% of P, from 0 to 0.10% of REM, from 0 to 0.01% in total of Cr, Zr, Hf, Nb and S, the balance Cu and unavoidable impurities. A number density of coarse secondary phase particles (particle diameter of 5 mm or more) is 10 per mmor less. A number density of fine secondary phase particles (particle diameter of from 5 to 10 nm) is 1.0·10per mmor more. A Si concentration in the parent phase is 0.10% by mass or more.