High strength titanium copper alloy, manufacturing method therefor, and terminal connector using the same

Abstract

A high strength titanium copper alloy consists of Ti at 2.0% by mass or more to 3.5% by mass or less; the balance of copper and inevitable impurities; an average grain size of 20 μm or less; and a 0.2% proof stress expressed by “b” of 800 N/mm 2 or more. The alloy further comprises a bending radius ratio (bending radius/sheet thickness) not causing cracking as expressed by “a” by a W-bending test in a transverse direction to a rolling direction, wherein “a” and “b” satisfy a≦0.05×b−40

What is claimed is:  
     
         1 . A high strength titanium copper alloy consisting of Ti at 2.0% by mass or more to 3.5% by mass or less; 
 the balance of copper and inevitable impurities; and    the average grain size of 20 μm or less;    the alloy further comprising a 0.2% proof stress expressed by “b” of 800 N/mm 2  or more; and    a bending radius ratio (bending radius/sheet thickness) not causing cracking as expressed by “a” by a W-bending test in a transverse direction to a rolling direction; 
 wherein “a” and “b” satisfy a≦0.05×b−40.  
   
     
     
         2 . A high strength titanium copper alloy consisting of Ti at 2.0% by mass or more to 3.5% by mass or less; 
 at least one of Zn, Cr, Zr, Fe, Ni, Sn, In, Mn, P, and Si at 0.01% by mass or more to 3.0% by mass or less in total; and    the balance of copper and inevitable impurities;    the alloy further comprising an average grain size of 20 μm or less;    a 0.2% proof stress expressed by “b” of 800 N/mm 2  or more; and    a bending radius ratio (bending radius/sheet thickness) not causing cracking as expressed by “a” by a W-bending test in a transverse direction to a rolling direction; 
 wherein “a” and “b” satisfy a≦0.05×b−40.  
   
     
     
         3 . The high strength titanium copper alloy according to  claim 1 , wherein the average grain size is in a range of 3 to 20 μm.  
     
     
         4 . The high strength titanium copper alloy according to  claim 1 , wherein the titanium copper alloy is obtained by performing final recrystallization annealing at a temperature below a borderline of an α-phase and an α+Cu 3 Ti phase.  
     
     
         5 . The high strength titanium copper alloy according to  claim 2 , wherein the titanium copper alloy is obtained by performing final recrystallization annealing at a temperature below a borderline of an α-phase and an α+Cu 3 Ti phase.  
     
     
         6 . A manufacturing method for a high strength titanium copper alloy according to  claim 1 , characterized by performing final recrystallization annealing at a temperature below a borderline of an α-phase and an α+Cu 3 Ti phase.  
     
     
         7 . A manufacturing method for a high strength titanium copper alloy according to  claim 2 , characterized by performing final recrystallization annealing at a temperature below a borderline of an α-phase and an α+Cu 3 Ti phase.  
     
     
         8 . The manufacturing method for a high strength titanium copper alloy according to claim  6 ; 
 wherein the alloy is cooled, after final recrystallization annealing, at a cooling rate of 100° C./sec or more;    cold worked at a working ratio of 5 to 70%; and    subjected to an aging process for 1 hour or more to 15 hours or less at a temperature of 300° C. or more to 600° C. or less.    
     
     
         9 . The manufacturing method for a high strength titanium copper alloy according to claim  7 ; 
 wherein the alloy is cooled, after final recrystallization annealing, at a cooling rate of 100° C./sec or more;    cold worked at a working ratio of 5 to 70%; and    subjected to an aging process for 1 hour or more to 15 hours or less at a temperature of 300° C. or more to 600° C. or less.    
     
     
         10 . A terminal connector using a high strength titanium copper alloy according to  claim 1 .  
     
     
         11 . A terminal connector using a high strength titanium copper alloy according to  claim 2 .  
     
     
         12 . A high strength titanium copper alloy which is subjected to an aging process after press working, the alloy consisting of: 
 Ti at 2.0% by mass or more to 3.5% by mass or less; and    the balance of copper and inevitable impurities;    the alloy further comprising a grain size of 5 to 15 μm; 
 wherein cracking does not occur by a W-bending test in a transverse direction to a rolling direction with a bending radius of zero before the aging process, and the hardness of the worked matrix after the aging process is 300 Hv or more.  
   
     
     
         13 . A high strength titanium copper alloy which is subjected to an aging process after press working, the alloy consisting of: 
 Ti at 2.0% by mass or more to 3.5% by mass or less;    at least one of Zn, Cr, Zr, Fe, Ni, Sn, In, Mn, P, and Si at 0.01% by mass or more to 3.0% by mass or less in total; and    the balance of copper and inevitable impurities;    the alloy further comprising a grain size of 5 to 15 μm; 
 wherein cracking does not occur by a W-bending test in a transverse direction to a rolling direction with a bending radius of zero before the aging process, and the hardness of the worked matrix after the aging process is 300 Hv or more.  
   
     
     
         14 . A manufacturing method for a high strength titanium copper alloy according to  claim 12 , comprising the steps of: 
 performing final recrystallization annealing at a temperature below a borderline of an α-phase and an α+Cu 3 Ti phase to adjust the grain size to 5 to 15 μm; and    performing final cold rolling at a working ratio of 5 to 50%.    
     
     
         15 . A manufacturing method for a high strength titanium copper alloy according to  claim 13 , comprising the steps of: 
 performing final recrystallization annealing at a temperature below a borderline of an α-phase and an α+Cu 3 Ti phase to adjust the grain size to 5 to 15 μm; and    performing final cold rolling at a working ratio of 5 to 50%.    
     
     
         16 . A terminal connector using a high strength titanium copper alloy according to  claim 12 .  
     
     
         17 . A terminal connector using a high strength titanium copper alloy according to  claim 13 .  
     
     
         18 . A high strength titanium copper alloy consisting of: 
 Ti at 2.0% by mass or more to 3.5% by mass or less; and    the balance of copper and inevitable impurities;    the alloy further comprising a tensile strength of 1200 MPa or more and an electrical conductivity of 10% IACS or more.    
     
     
         19 . A high strength titanium copper alloy consisting of: 
 Ti at 2.0% by mass or more to 3.5% by mass or less;    Zn at 0.05% by mass or more to 2.0% by mass or less;    at least one of Cr, Zr, Fe, Ni, Sn, In, Mn, P, and Si at 0.01% by mass or more to 3.0% by mass or less in total; and    the balance of copper and inevitable impurities;    the alloy further comprising a tensile strength of 1200 MPa or more and an electrical conductivity of 10% IACS or more.    
     
     
         20 . A manufacturing method for a high strength titanium copper alloy according to  claim 18 , comprising the steps of: 
 hot rolling at a temperature of 600° C. or more;    cold rolling successively at a working ratio of 95% or more; and    aging at a temperature of 340° C. or more to less than 480° C. for 1 hour or more to less than 15 hours while maintaining an agglomerated matrix after the cold rolling.    
     
     
         21 . A manufacturing method for a high strength titanium copper alloy according to  claim 19 , comprising the steps of: 
 hot rolling at a temperature of 600° C. or more;    cold rolling successively at a working ratio of 95% or more; and    aging at a temperature of 340° C. or more to less than 480° C. for 1 hour or more to less than 15 hours while maintaining an agglomerated matrix after the cold rolling.    
     
     
         22 . A fork-shaped connector using a high strength titanium copper alloy according to  claim 18 .  
     
     
         23 . A fork-shaped connector using a high strength titanium copper alloy according to  claim 19 .  
     
     
         24 . A high strength titanium copper alloy which is subjected to an aging process after press working, the alloy consisting of: 
 Ti at 2.0% by mass or more to 3.5% by mass or less; and    the balance of copper and inevitable impurities;    the alloy further comprising a worked matrix having a hardness of 345 Hv or more after the aging process.    
     
     
         25 . A high strength titanium copper alloy which is subjected to an aging process after press working, the alloy consisting of: 
 Ti at 2.0% by mass or more to 3.5% by mass or less;    Zn at 0.05% by mass or more to 2.0% by mass or less;    at least one of Cr, Zr, Fe, Ni, Sn, In, Mn, P, and Si at 0.01% by mass or more to 3.0% by mass or less in total; and    the balance of copper and inevitable impurities;    the alloy further comprising a worked matrix having a hardness of 345 Hv or more after the aging process.    
     
     
         26 . A manufacturing method for a high strength titanium copper alloy according to  claim 24 , comprising the steps of: 
 hot rolling at a temperature of 600° C. or more; and    cold rolling successively at a working ratio of 95% or more.    
     
     
         27 . A manufacturing method for a high strength titanium copper alloy according to  claim 25 , comprising the steps of: 
 hot rolling at a temperature of 600° C. or more; and    cold rolling successively at a working ratio of 95% or more.    
     
     
         28 . A fork-shaped connector using a high strength titanium copper alloy according to  claim 24 .  
     
     
         29 . A fork-shaped connector using a high strength titanium copper alloy according to claim  25 .