Copper alloy for an electric connecting device

Abstract

A copper alloy for an electric connecting device, having Cr in the range from 0.1 to 1 mass %, Zn in the range from 0.1 to 5.0 mass %, and Sn in the range from 0.1 to 2.0 mass %, with the balance being inevitable impurities and Cu, wherein the copper alloy has tensile strength of 600 MPa or more, 0.2% yield strength of 560 MPa or more, electric conductivity of 40% IACS or more, and rupture time of 500 hours or more in a stress corrosion test under a load of 80% of the 0.2% yield strength.

1 . A copper alloy for an electric connecting device, comprising Cr in the range from 0.1 to 1 mass %, Zn in the range from 0.1 to 5.0 mass %, and Sn in the range from 0.1 to 2.0 mass %, with the balance being inevitable impurities and Cu, wherein the copper alloy has tensile strength of 600 MPa or more, 0.2% yield strength of 560 MPa or more, electric conductivity of 40% IACS or more, and rupture time of 500 hours or more in a stress corrosion test under a load of 80% of the 0.2% yield strength. 
     
     
         2 . The copper alloy for an electric connecting device as claimed in  claim 1 , which has stress relaxation property of 50% or less, in 1,000 hours at 150° C. 
     
     
         3 . The copper alloy for an electric connecting device as claimed in  claim 1 , comprising Si in the range from exceeding zero to 0.2 mass %. 
     
     
         4 . The copper alloy for an electric connecting device as claimed in  claim 2 , which is excellent in glow resistance.