Copper alloy and method of producing the same

Abstract

A copper alloy, having Sn 3.0 to 13.0 mass %, with the balance being Cu and unavoidable impurities, which copper alloy contains crystal grains whose diameter is 1.0 to 2.0 μm, and wherein the copper alloy has a precipitate X having a diameter of 1 to 50 nm and a density of 10 6 to 10 10 per mm 2 , and a precipitate Y having a diameter of 50 to 500 nm and a density of 10 4 to 10 8 per mm 2 ; and a method of producing the copper alloy, including the steps of: cold-working the recrystallized structure with an average crystal grain diameter of 1 to 15 μm at a working ratio of 40 to 70%; and heating the resultant to obtain a recrystallized structure with a crystal grain diameter of 1 to 2 μm.

1 . A copper alloy, comprising Sn 3.0 to 13.0 mass %, with the balance being Cu and unavoidable impurities, which copper alloy contains crystal grains whose diameter is 1.0 to 2.0 μm, 
 wherein the copper alloy has a precipitate X having a diameter of 1 to 50 nm and a density of 10 6  to 10 10  per mm 2 , and a precipitate Y having a diameter of 50 to 500 nm and a density of 10 4  to 10 8  per mm 2 .    
   
   
       2 . The copper alloy according to  claim 1 , wherein the precipitates X and Y each are composed of P and at least one element among Mn, Mg, Cr, W, Co, B, Ni, Fe, Ca, Si, Cu, Ti, Zr, and Al.  
   
   
       3 . The copper alloy according to  claim 1 , wherein the precipitates X and Y each are composed of at least two elements among Mn, Mg, Cr, W, Co, B, Ni, Fe, Ca, Si, Cu, Ti, Zr, and Al.  
   
   
       4 . The copper alloy according to  claim 1 , wherein the precipitates X and Y each are composed of Fe, Ni, and P.  
   
   
       5 . An electronic and electric instrument part, comprising the copper alloy according to  claim 1 .  
   
   
       6 . A method of producing the copper alloy according to  claim 1 , wherein the method comprises the steps of; 
 cold-working a recrystallized structure with an average crystal grain diameter of 1 to 15 μm at a working ratio of 40 to 70%; and    heating the resultant to obtain a recrystallized structure with a crystal grain diameter of 1 to 2 μm.