Copper-based alloy and method of manufacturing same

Abstract

This invention is a copper-based alloy for use in connectors, lead frames, switches and relays and the like that has a superior balance of conductivity, tensile strength and workability in bending and method of manufacturing same. The alloy is manufactured by taking an ingot of a copper-based alloy containing Ni, Sn, P and also at least one or more elements selected from a group consisting of Zn, Si, Fe, Co, Mg, Ti, Cr, Zr and Al in a total amount of 0.01-30 wt. % with the remainder being Cu and unavoidable impurities, performing a combination process of cold rolling followed by annealing at least one time and then performing cold rolling at a percent reduction Z that satisfies the following Formula (1): Z<100−10X−Y   (1) [where Z is the percent cold reduction (%), X is the Sn content (wt. %) among the various elements, and Y is the total content (wt. %) of all elements other than Sn and Cu] followed by low-temperature annealing performed at a temperature below the recrystallization temperature. This causes dispersion and precipitation of Ni—P compounds so that a precipitation-strengthened type copper-based alloy with an x-ray diffraction intensity ratio of the surface SND as given by the following formula is 0.05≦SND≦0.15 [provided that SND=I{200}÷[I{111}+I{220}+I{311}], where I{200} is the x-ray diffraction intensity of the {100} plane, I{111} is the x-ray diffraction intensity of the {111} plane, I{220} is the x-ray diffraction intensity of the {110} plane, and I{311} is the x-ray diffraction intensity of the {311} plane] and a superior balance of conductivity, tensile strength, 0.2% yield strength, springiness, Vickers hardness and bending workability is obtained.

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