Abstract: A copper alloy according to the present invention is a copper alloy rolled to be plate-shaped. The copper alloy contains 8.5 to 9.5 mass % of Ni, 5.5 to 6.5 mass % of Sn with a remainder being Cu and unavoidable impurities. An average diameter of crystal grains in a cross section perpendicular to a rolling direction is less than 6 ?m. A ratio x/y of an average length x of the crystal grains in a plate width direction to an average length y in a plate thickness direction satisfies 1?x/y?2.5. An X-ray diffracted intensity ratio in a plate surface parallel to the rolling direction of the copper alloy includes, when an X-ray diffracted intensity of a (220) plane is standardized as 1, an intensity ratio of a (200) plane being 0.30 or less, an intensity ratio of a (111) plane being 0.45 or less, and an intensity ratio of a (311) plane being 0.60 or less. The intensity ratio of the (111) plane is greater than the intensity ratio of the (200) plane and smaller than the intensity ratio of the (311) plane.

Abstract: To obtain a copper alloy having a tensile strength of 700 N/mm2 or more and a conductivity of 60% IACS or more, a copper alloy of the present invention comprises from 0.8 mass % to 1.8 mass % of Co, from 0.16 mass % to 0.6 mass % of Si, and the balance of Cu and unavoidable impurities, in which a mass ratio of Co to Si (Co/Si) is between 3.0 and 5.0; a size of inclusions to be precipitated in the copper alloy is 2 ?m or less; and a total volume of the inclusions having a size of between 0.05 ?m and 2 ?m in the copper alloy is 0.5 vol % or less.

Abstract: Raw materials for a copper alloy are melted in a high frequency smelter and cast, and milling, rolling, and annealing are carried out. Then, rolling is again carried out. Thereafter, the materials are heated at a temperature of 900° C. for one minute and are quenched in water, to be solution treated. Subsequently, the materials are heated at a temperature of 500° C. for five hours for aging, and then are cooled at a cooling rate in a range of 10 to 50° C. per hour until the materials are cooled to a temperature of 380° C.

Abstract: Raw materials for a copper alloy are melted in a high frequency smelter and cast, and milling, rolling, and annealing are carried out. Then, rolling is again carried out. Thereafter, the materials are heated at a temperature of 900° C. for one minute and are quenched in water, to be solution treated. Subsequently, the materials are heated at a temperature of 500° C. for five hours for aging, and then are cooled at a cooling rate in a range of 10 to 50° C. per hour until the materials are cooled to a temperature of 380° C.

Abstract: Raw materials for a copper alloy are melted in a high frequency smelter and cast, and milling, rolling, and annealing are carried out. Then, rolling is again carried out. Thereafter, the materials are heated at a temperature of 900° C. for one minute and are quenched in water, to be solution treated. Subsequently, the materials are heated at a temperature of 500° C. for five hours for aging, and then are cooled at a cooling rate in a range of 10 to 50° C. per hour until the materials are cooled to a temperature of 380° C.

Abstract: To obtain a copper alloy having a tensile strength of 700 N/mm2 or more and a conductivity of 60% IACS or more, a copper alloy of the present invention comprises from 0.8 mass % to 1.8 mass % of Co, from 0.16 mass % to 0.6 mass % of Si, and the balance of Cu and unavoidable impurities, in which a mass ratio of Co to Si (Co/Si) is between 3.0 and 5.0; a size of inclusions to be precipitated in the copper alloy is 2 ?m or less; and a total volume of the inclusions having a size of between 0.05 ?m and 2 ?m in the copper alloy is 0.5 vol % or less.

Abstract: Raw materials for a copper alloy are melted in a high frequency smelter and cast, and milling, rolling, and annealing are carried out. Then, rolling is again carried out. Thereafter, the materials are heated at a temperature of 900° C. for one minute and are quenched in water, to be solution treated. Subsequently, the materials are heated at a temperature of 500° C. for five hours for aging, and then are cooled at a cooling rate in a range of 10 to 50° C. per hour until the materials are cooled to a temperature of 380° C.

Abstract: The present invention provides a copper alloy for electronic part which is excellent in adhesion of silver(Ag) and reliability of solderability and adhesion of plating without impairing excellent strength and electrical conductivity of a copper-nickel-silicon alloy. The copper alloy for electronic parts in the present invention consist essentially of 1.7 to 4.0% by weight of nickel, 0.3 to 0.8% by weight of silicon, 0.002 to 0.3% by weight of silver, 0.5 to 2.0% by weight of zinc, and a residual of copper.