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 <100−10 X−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 S ND as given by the following formula is 0.05≦S ND ≦0.15 [provided that S ND =I{200}÷[I{111}+I{220}+I{311}], where I{200} is the x-ray diffraction intensity of the {100} plane, {111} is the x-ray diffraction intensity of the {111} plane, I{220} is the x-ray diffraction intensity of the {110} plane, and {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.

1 . 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, where the x-ray diffraction intensity ratio of the surface S ND  is such that 0.05≦S ND ≦0.15 [provided that S ND =l{200}÷[l{111}+l{220}+l{311}], where l{200} is the x-ray diffraction intensity of the {100} plane, l{111} is the x-ray diffraction intensity of the {111} plane, l{220} is the x-ray diffraction intensity of the {110} plane, and l{311} is the x-ray diffraction intensity of the {311} plane].  
     
     
         2 . A copper-based alloy containing Ni: 0.01-4.0 wt. %, Sn: 0.01-10 wt. % and P: 0.01-0.20 wt. % with the remainder being Cu and unavoidable impurities, where the x-ray diffraction intensity ratio of the surface S ND  is such that 0.05≦S ND ≦0.15 [provided that S ND =l{200}÷[l{111}+l{220}+l{311}], where l{200} is the x-ray diffraction intensity of the {100} plane, l{111} is the x-ray diffraction intensity of the {111} plane, l{220} is the x-ray diffraction intensity of the {110} plane, and l{311} is the x-ray diffraction intensity of the {311} plane].  
     
     
         3 . A copper-based alloy containing Ni: 0.01-4.0 wt. %, Sn: 0.01-10 wt. % and P: 0.01-0.20 wt. % 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, where the x-ray diffraction intensity ratio of the surface S ND  is such that 0.05≦S ND ≦0.15 [provided that S ND =l{200}-[l{111}+l{220}+l{311}], where l{200} is the x-ray diffraction intensity of the {100} plane, l{111} is the x-ray diffraction intensity of the {111} plane, l{220} is the x-ray diffraction intensity of the {110} plane, and l{311} is the x-ray diffraction intensity of the {311} plane].  
     
     
         4 . A method of manufacturing a copper-based alloy according to  claim 1 , comprising the steps of: taking an ingot of a copper-based alloy having the indicated elemental composition, performing a combination process of cold rolling followed by annealing at least one time and then performing intermediate rolling which is a rolling process prior to a final cold rolling process, thereby making the x-ray diffraction intensity ratio of the sheet surface S ND  such that 0.05≦S ND ≦0.15, and thereafter performing annealing to obtain sheet with a grain size of 20 μm or less, and then performing the final cold rolling and low-temperature annealing at a temperature below the recrystallization temperature.  
     
     
         5 . A method of manufacturing a copper-based alloy according to  claim 1 , comprising the steps of: taking an ingot of a copper-based alloy having the indicated elemental composition, 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< 100−10 X−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.  
     
     
         6 . A method of manufacturing a copper-based alloy according to  claim 1 , comprising the steps of: taking an ingot of a copper-based alloy having the indicated elemental composition, 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):  
         0.8(100−10 X−Y )< Z< 100−10 X−Y   (2)  
       [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.  
     
     
         7 . A method according to  claim 4  wherein, prior to performing the combination process, at least one process selected in advance from among homogenization annealing and hot rolling is performed on the ingot.