Copper alloy sheet material

Abstract

A copper alloy sheet material which has a tensile strength of 730-820 MPa and contains at least nickel (Ni) and silicon (Si), with the remainder being copper (Cu) and inevitable impurities. When the sheet material has a shape capable of 180° tight bending and the width and thickness of this sheet material are expressed by W (unit: mm) and T (unit: mm) respectively, then the product of W and T is 0.16 or less. Preferably, the sheet material is constituted of an alloy containing nickel at 1.8-3.3 mass %, silicon at 0.4 mass %, and chromium (Cr) at 0.01-0.5 mass %, with the remainder being copper and inevitable impurities. The sheet material may further contain one or more of: at least one member selected among tin (Sn), magnesium (Mg), silver (Ag), manganese (Mn), titanium (Ti), iron (Fe), and phosphorus (P) in a total amount of 0.01-1 mass %; zinc (Zn) at 0.01-10 mass %, cobalt (Co) at and 0.01-1.5 mass %.

1 .- 7 . (canceled) 
     
     
         8 . A copper alloy sheet material having a tensile strength of 730 to 820 MPa, and comprising at least Ni and Si in addition to copper and inevitable impurities, wherein when the material is capable of 180° tight bending and the sheet width is taken to be W (unit: mm) and the sheet thickness is taken to be T (unit: mm), the product of W and T (unit: mm 2 ) is 0.16 or less. 
     
     
         9 . The copper alloy sheet material of  claim 8 , wherein second-phase particles existing on a grain boundary exist at a density of 10 4  to 10 8  particles/mm 2 , and the average grain size is 10 μm or less. 
     
     
         10 . The copper alloy sheet material of  claim 8 , wherein the value of ratio r/f of the particle size r (unit: μm) of second-phase particles inside the grain and on the grain boundary and the volume fraction f of the particles is at least 1 and not more than 100, and the average grain size is 10 μm or less. 
     
     
         11 . The copper alloy sheet material of  claim 9 , wherein of said second-phase particles, the ratio of particles comprising Cr as a constituent element is 50% or more. 
     
     
         12 . The copper alloy sheet material of  claim 10 , wherein of said second-phase particles, the ratio of particles comprising Cr as a constituent element is 50% or more. 
     
     
         13 . The copper alloy sheet material of  claim 8 , wherein the alloy composition includes Ni at 1.8 to 3.3 mass %, Si at 0.4 to 1.1 mass % and Cr at 0.01 to 0.5 mass %, with the remainder being Cu and inevitable impurities. 
     
     
         14 . The copper alloy sheet material of  claim 9 , wherein the alloy composition includes Ni at 1.8 to 3.3 mass %, Si at 0.4 to 1.1 mass % and Cr at 0.01 to 0.5 mass %, with the remainder being Cu and inevitable impurities. 
     
     
         15 . The copper alloy sheet material of  claim 10 , wherein the alloy composition includes Ni at 1.8 to 3.3 mass %, Si at 0.4 to 1.1 mass % and Cr at 0.01 to 0.5 mass %, with the remainder being Cu and inevitable impurities. 
     
     
         16 . The copper alloy sheet material of  claim 11 , wherein the alloy composition includes Ni at 1.8 to 3.3 mass %, Si at 0.4 to 1.1 mass % and Cr at 0.01 to 0.5 mass %, with the remainder being Cu and inevitable impurities. 
     
     
         17 . The copper alloy sheet material of  claim 12 , wherein the alloy composition includes Ni at 1.8 to 3.3 mass %, Si at 0.4 to 1.1 mass % and Cr at 0.01 to 0.5 mass %, with the remainder being Cu and inevitable impurities. 
     
     
         18 . The copper alloy sheet material of  claim 13 , comprising one kind or two kinds or more elements from among at least one of Sn, Mg, Ag, Mn, Ti, Fe and P at 0.01 to 1 mass %, Zn at 0.01 to 10 mass % and Co at 0.01 to 1.5 mass %. 
     
     
         19 . The copper alloy sheet material of  claim 14 , comprising one kind or two kinds or more elements from among at least one of Sn, Mg, Ag, Mn, Ti, Fe and P at 0.01 to 1 mass %, Zn at 0.01 to 10 mass % and Co at 0.01 to 1.5 mass %. 
     
     
         20 . The copper alloy sheet material of  claim 15 , comprising one kind or two kinds or more elements from among at least one of Sn, Mg, Ag, Mn, Ti, Fe and P at 0.01 to 1 mass %, Zn at 0.01 to 10 mass % and Co at 0.01 to 1.5 mass %. 
     
     
         21 . The copper alloy sheet material of  claim 16 , comprising one kind or two kinds or more elements from among at least one of Sn, Mg, Ag, Mn, Ti, Fe and P at 0.01 to 1 mass %, Zn at 0.01 to 10 mass % and Co at 0.01 to 1.5 mass %. 
     
     
         22 . The copper alloy sheet material of  claim 17 , comprising one kind or two kinds or more elements from among at least one of Sn, Mg, Ag, Mn, Ti, Fe and P at 0.01 to 1 mass %, Zn at 0.01 to 10 mass % and Co at 0.01 to 1.5 mass %. 
     
     
         23 . The copper alloy sheet material of  claim 8 , wherein when the material is maintained at 165° C. for 3000 hours, the stress relaxation rate is 30% or less. 
     
     
         24 . The copper alloy sheet material of  claim 9  or  10 , wherein when the material is maintained at 165° C. for 3000 hours, the stress relaxation rate is 30% or less. 
     
     
         25 . The copper alloy sheet material of  claim 11  or  12 , wherein when the material is maintained at 165° C. for 3000 hours, the stress relaxation rate is 30% or less. 
     
     
         26 . The copper alloy sheet material of any one of the  claims 13  to  17 , wherein when the material is maintained at 165° C. for 3000 hours, the stress relaxation rate is 30% or less. 
     
     
         27 . The copper alloy sheet material of any one of the  claims 18  to  22 , wherein when the material is maintained at 165° C. for 3000 hours, the stress relaxation rate is 30% or less.