Patent ID: 7909946

Claim:
A casted copper alloy, consisting essentially of Cu: 69 to 88 mass %, Si: 2 to 5 mass %, Zr: 0.0005 to 0.04 mass %, P: 0.01 to 0.25 mass %, and Zn: the balance; having relation of, in terms of a content of an element a, [a] mass %, f0=[Cu]−3.5[Si]−3[P]=61 to 71, f1=[P]/[Zr]=0.7 to 200, f2=[Si]/[Zr]=75 to 5000, and f3=[Si]/[P]=12 to 240; wherein the copper alloy has a metal structure that contains α phase and one or more additional phases selected from the group consisting of (i) K phase, (ii) γ phase, (iii) K phase and γ phase, (iv) β phase, and (v) μ phase, and having relation of, in terms of a content of a phase b, [b]%, in an area rate, f4=[α]+[γ]+[K]≧85 and f5=[γ]+[K]+0.3[μ]−[β]=5 to 95; and the copper alloy has an average grain diameter of 200 μm or less in a macrostructure obtained when melted and solidified during casting.