Titanium copper alloy having excellent strength and bendability, and manufacturing method thereof

Abstract

A titanium copper alloy having excellent strength and bendability comprising 1.0 to 4.5% by mass of Ti, the balance of copper and inevitable impurities, characterized in that; diameters of the intermetallic compound particles consisting of Cu and Ti precipitated in the alloy are 3 μm or less; the average number of the intermetallic compound particles having the diameters of 0.2 to 3 μm is 700 or less per a cross-sectional area of 1000 μm 2 in a transverse direction to a rolling direction; the average grain size measured in the above cross-sectional area is 10 μm or less; and a tensile strength is 890 MPa or more.

What is claimed is:  
     
         1 . A titanium copper alloy having excellent strength and bendability characterized in that; 
 it comprises 1.0 to 4.5% by mass of Ti, the balance of copper and inevitable impurities;    diameters of intermetallic compound particles consisting of Cu and Ti precipitated in the alloy are 3 μm or less;    the average number of said intermetallic compound particles having the lo diameters of 0.2 to 3 μm is 700 or less per a cross-sectional area of 1000 μm 2  in a transverse direction to a rolling direction;    the average grain size measured in a cross-sectional area in a transverse direction to a rolling direction is 10 μm or less; and    a tensile strength is 890 MPa or more.    
     
     
         2 . The titanium copper alloy according to  claim 1 , wherein the average number of the intermetallic compound particles having the diameters of 0.2 to 3 μm is 6 to 700 per a cross-sectional area of 1000 μm 2  in a transverse direction to a rolling direction.  
     
     
         3 . A manufacturing method of the titanium copper alloy according to  claim 1  or  2  comprising a hot rolling, a cold rolling, a solution treatment, a cold rolling and an aging treatment, of a titanium copper alloy ingot in this order characterized in that; 
 the ingot is heated at a temperature of 850 to 950° C. for 30 minutes or more before the hot rolling and then the ingot is hot rolled and the temperature in the end of the hot rolling is 700° C. or more;  
 in the solution treatment, the material is annealed at a temperature in a range between (T−50) ° C. and (T+10) ° C., wherein T is a temperature at which the solubility of Ti in Cu is equal to the concentration of Ti contained in the alloy; and thereafter  
 the annealed material is cooled at a cooling rate of 100° C./sec or more.  
 
     
     
         4 . A manufacturing method of the titanium copper alloy according to  claim 3 , wherein a reduction ratio in the cold rolling between the solution treatment and the aging treatment is 50% or less.  
     
     
         5 . A manufacturing method of the titanium copper alloy according to  claim 3  or  4 , wherein the aging treatment is conducted at a temperature of 300 to 600° C.