Copper alloy material

Abstract

A copper alloy material consists of, by mass % Ti: 0.01-2.5%, Cr: 0.01-0.5%, Fe: 0.01% or more and less than 1%, and the balance Cu and impurities. The copper alloy possesses excellent strength, electrical conductivity, and workability without containing any environmentally harmful elements. These properties are attained by control of the total number and the diameter of precipitates and inclusions having a diameter of 1 μm, and control of the relationship between tensile strength TS (MPa) and electrical conductivity, IACS (%). The copper alloy material is a sheet and the relationship between tensile strength and the bending workability in a bad way B 90 of the copper alloy material as well as the relationship between elongation and tensile strength are also controlled with respect to each other for property improvement.

1 . A copper alloy material characterized by the following (A) to (F):
 (A) a copper alloy consists of, by mass %, not less than 0.01% and not more than 2.5% of Ti, not less than 0.01 and not more than 0.5% of Cr, not less than 0.01 and less than 1% of Fe and the balance Cu and impurities;   (B) the relationship between the total number N and the diameter X satisfies the following formula (1):
   log  N≦ 0.4742+17.629×exp(−0.1133× X )  (1) 
   (C) and the relationship between tensile strength TS(MPa) and electrical conductivity IACS (%), satisfies the following formula (2):
     TS≧ 6 48.06+985.48×exp(−0.0513× IACS )  (2) 
 wherein, 
   (D) when the copper alloy material is sheet possessing a tensile strength of 600 MPa or less, the bending workability of the copper alloy material satisfies the following formula (3):
   B 90 ≦2.0  (3) 
   (E) when the copper alloy material is sheet possessing a tensile strength of 600 MPa or more, the bending workability of the copper alloy material satisfies the following formula (4):
     B   90 ≦25.093−54.82×exp[−{( TS+ 583.61)/1254} 2 ]+1.25× t   (4) 
   (F) and when the copper alloy material is other than sheet, the relationship between elongation El(%) and tensile strength, TS(MPa) of the copper alloy material satisfies the following formula (5):
     El≧ 24.138−24.6076×exp[−{( TS− 1816.36)/2213.52} 2 ]  (5) 
 where 
 N denotes the total number of precipitates and inclusions having a diameter of 1 μm or more within 1 mm 2 , unit area of the copper alloy material; 
 X denotes the diameter in μm of precipitates and inclusions having diameter of 1 μm or more; 
 TS denotes the tensile strength (MPa); 
 IACS denotes the electrical conductivity (%); 
 B 90  denotes the bending workability in the 90° bend test; 
 t denotes the thickness (mm); and 
 El denotes the elongation (%), and 
 B 90 , TS, and El signify values when specimens were taken with the specimen long side perpendicular to the rolling direction. 
   
   
   
       2 . The copper alloy material according to  claim 1 , further containing not less than 0.005% and not more than 1% of Ag. 
   
   
       3 . The copper alloy material according to  claim 1 , further containing not less than 0.01% and not more than 1.0% of one or more elements selected from Sn, Mn, Co, Al, Si, Nb, Ta, Mo, V, W, Au, Zn, Ni, Te, Se, and Ge, and the total content of these elements is not more than 1.0%. 
   
   
       4 . The copper alloy material according to  claim 2 , further containing not less than 0.01% and not more than 1.0% of one or more elements selected from Sn, Mn, Co, Al, Si, Nb, Ta, Mo, V, W, Au, Zn, Ni, Te, Se, and Ge, and the total content of these elements is not more than 1.0%. 
   
   
       5 . The copper alloy material according  claim 1 , further containing not less than 0.001% and not more than 0.1% in total of one or more elements selected from Zr, Mg, Li, Ca, and rare earth elements. 
   
   
       6 . The copper alloy material according  claim 2 , further containing not less than 0.001% and not more than 0.1% in total of one or more elements selected from Zr, Mg, Li, Ca, and rare earth elements. 
   
   
       7 . The copper alloy material according  claim 3 , further containing not less than 0.001% and not more than 0.1% in total of one or more elements selected from Zr, Mg, Li, Ca, and rare earth elements. 
   
   
       8 . The copper alloy material according  claim 4 , further containing not less than 0.001% and not more than 0.1% in total of one or more elements selected from Zr, Mg, Li, Ca, and rare earth elements.