Copper alloy for electric and electronic device, copper alloy sheet for electric and electronic device, conductive component for electric and electronic device, and terminal

A copper alloy for electric and electronic devices, the copper alloy comprising:

• Zn at more than 2 mass % and less than 23 mass %;
• Sn at 0.1 mass % or more and 0.9 mass % or less;
• Ni at 0.05 mass % or more and lower than 1.0 mass %;
• Fe at 0.001 mass % or more and lower than 0.10 mass %;
• Co at 0.001 mass % or more and lower than 0.1 mass %;
• P at 0.005 mass % or more and 0.1 mass % or less;
• and
• a balance including Cu and unavoidable impurities,
• wherein a ratio (Fe+Co)/Ni of a total content of (Fe+Co) of Fe and Co to a Ni content satisfies 0.002≦(Fe+Co)/Ni<1.5 by atomic ratio,
• a ratio (Ni+Fe+Co)/P of a total content (Ni+Fe+Co) of Ni, Fe, and Co to a P content satisfies 3<(Ni+Fe+Co)/P<15 by atomic ratio,
• a ratio Sn/(Ni+Fe+Co) of a Sn content to the total content (Ni+Fe+Co) of Ni, Fe, and Co satisfies 0.3<Sn/(Ni+Fe+Co)<5 by atomic ratio, and
• a special grain boundary length ratio, Lσ/L, is 10% or more, Lσ/L being a ratio of Lσ to L, Lσ being a sum of each grain boundary length of:
• Σ3;
• Σ9;
• Σ27a;
• and Σ27b special grain boundaries, and L being a length of all crystal grain boundaries, in a case where an α phase containing Cu, Zn and Sn within a measurement area of 1000 μm2 or larger is measured by EBSD method with a measurement interval of 0.1 μm a step;
• data analysis is performed excluding measurement points with a CI value at 0.1 or less, the CI value being analyzed by a data analysis software OIM;
• and a grain boundary is identified between adjacent measurement points with a misorientation exceeding 15°.