Method for fabricating a copper alloy and copper alloy fabricated by the same

Abstract

A method for fabricating a copper alloy. Cu and Cr, Zr, and Sn to be doped to the Cu are melt to cast a copper alloy material. Hot working is carried out on the copper alloy material to form a plate material having a rolled texture. Heat treatment is carried out on the plate material. Cold rolling with workability of 80% or more and less than 90% is carried out on the plate material after the heat treatment to form an intermediate plate material. Aging treatment is carried out on the intermediate plate material. Another cold rolling with workability of 20% to 40% is carried out as finish rolling on the intermediate plate material after the aging treatment step. The intermediate plate material after the finish rolling step is heated as stress relief annealing.

1 . A method for fabricating a copper alloy comprising:
 melting step of melting Cu and Cr, Zr, and Sn to be doped to the Cu to cast a copper alloy material;   hot working step of carrying out a hot working on the copper alloy material to form a plate material having a rolled texture;   heat treatment step of carrying out a heat treatment on the plate material;   intermediate rolling step of carrying out a cold rolling with a workability of 80% more and less than 90% on the plate material after the heat treatment step to form an intermediate plate material;   aging treatment step of carrying out an aging treatment on the intermediate plate material;   finish rolling step of carrying out another cold rolling with a workability of 20% to 40% on the intermediate plate material after the aging treatment step; and   stress relief annealing step of carrying out a heating on the intermediate plate material after the finish rolling step.   
     
     
         2 . The method for fabricating a copper alloy according to  claim 1 , wherein the heat treatment step comprises carrying out the heat treatment at such a temperature that the rolled texture is reduced by generating recrystallization in the rolled texture while suppressing coarsening of a grain size of crystal in the plate material. 
     
     
         3 . The method for fabricating a copper alloy, according to  claim 2 , wherein the heat treatment step comprises carrying out the heat treatment at such a temperature that a grain size of a copper alloy crystal contained in the copper alloy is 50 μm or less. 
     
     
         4 . The method for fabricating a copper alloy, according to  claim 3 , wherein the temperature of the heat treatment is 700° C. or more and less than 950° C. 
     
     
         5 . The method for fabricating a copper alloy, according to  claim 1 , wherein the aging treatment step comprises carrying out the aging treatment at a temperature of 390° C. to 450° C. on the intermediate plate material. 
     
     
         6 . The method for fabricating a copper alloy, according to  claim 1 , wherein the stress relief annealing step comprises carrying out the heating at a temperature of 400° C. to 600° C. on the intermediate plate material. 
     
     
         7 . The method for fabricating a copper alloy according to  claim 1 , wherein the melting step comprises casting the copper alloy material comprising the Cr of 0.1 to 0.4% by weight, the Zr of 0.02 to 0.2% by weight, and the Sn of 0.01 to 0.3% by weight. 
     
     
         8 . The method for fabricating a copper alloy, according to  claim 1 , further comprising:
 rough rolling step of carrying out a further cold rolling on the plate material,   wherein the heat treatment step comprises carrying out the heat treatment on the plate material after the rough rolling step.   
     
     
         9 . The method for fabricating a copper alloy, according to  claim 2 , wherein the heat treatment step comprises carrying out the heat treatment at such a temperature that a grain size of a copper alloy crystal contained in the copper alloy is 30 μm or less. 
     
     
         10 . The method for fabricating a copper alloy, according to  claim 9 , wherein the temperature of the heat treatment is 700° C. or more and less than 850° C. 
     
     
         11 . A copper alloy comprising:
 Cr of 0.1 to 0.4% by weight, the Zr of 0.02 to 0.2% by weight, and the Sn of 0.01 to 0.3% by weight, a balance being Cu and inevitable impurities.   
     
     
         12 . The copper alloy, according to  claim 11 , wherein the copper alloy has an electric conductivity of 80% IACS or more and a strength of 550 MPa or more.