Copper alloy material and method of making same

Abstract

A copper alloy material having: 1.0 to 5.0 mass % of Ni; 0.2 to 1.0 mass % of Si; 1.0 to 5.0 mass % of Zn; 0.1 to 0.5 mass % of Sn; 0.003 to 0.3 mass % of P; and the balance consisting of Cu and an unavoidable impurity. The mass ratio between Ni and each of Si, Zn and Sn is to be Ni/Si=4 to 6, Zn/Ni=0.5 or more, and Sn/Ni=0.05 to 0.2.

1 . A copper alloy material, comprising: 
 1.0 to 5.0 mass % of Ni;    0.2 to 1.0 mass % of Si;    1.0 to 5.0 mass % of Zn;    0.1 to 0.5 mass % of Sn;    0.003 to 0.3 mass % of P; and    the balance consisting of Cu and an unavoidable impurity,    wherein a mass ratio between Ni and each of Si, Zn and Sn is to be Ni/Si=4 to 6, Zn/Ni=0.5 or more, and Sn/Ni=0.05 to 0.2.    
   
   
       2 . The copper alloy material according to  claim 1 , wherein: 
 the copper alloy material comprises a tensile strength of 800 N/mm 2  or more.    
   
   
       3 . The copper alloy material according to  claim 1 , wherein: 
 the copper alloy material comprises an elongation of 8% or more.    
   
   
       4 . The copper alloy material according to  claim 1 , wherein: 
 the copper alloy material comprises a conductivity of 35% IACS or more.    
   
   
       5 . A method of making the copper alloy material as defined in  claim 1 , comprising: 
 preparing a copper alloy raw material with the same composition and the same mass ratio as defined in  claim 1;     a first cold rolling step that the copper alloy raw material is cold-rolled down to a thickness of 1.3 to 1.7 times thicker than a target thickness of a final product;    a first heat treatment step that the cold-rolled material in the first cold rolling step is heated up to 700 to 900° C. and then cooled to 300° C. or less at a cooling rate of 25° C./min or more;    a second cold rolling step that the treated material in the first heat treatment step is cold-rolled down to the target thickness;    a second heat treatment step that the cold-rolled material in the second cold rolling step is heated up to 400 to 500° C. and held for 30 min. to 10 hrs.; and    a third heat treatment step that the treated material in the second heat treatment step is heated at 400 to 550° C. for 10 sec. to 3 min. while applying a tension of 10 to 100 N/mm 2  in its longitudinal direction.