Age-hardenable copper alloy

Abstract

An age-hardenable copper alloy made of 1.2 to 2.7% cobalt, which is able to be partially replaced by nickel, 0.3 to 0.7% beryllium, 0.01 to 0.5% zirconium, optionally 0.005 to 0.1% magnesium and/or iron and in some instances up to a maximum of 0.15% of at least one element from the group including niobium, tantalum, vanadium, hafnium, chromium, manganese, titanium and cerium. The remainder is copper and includes production-conditioned impurities and usual processing additives. This copper alloy is used as the material for producing mold blocks for the side dams of continuous strip-casting installations.

What is claimed is:  
     
         1 . An age-hardenable copper alloy suitable as a material for producing block for the side dams of strip-casting installations, comprising: 1.2 to 2.7% cobalt, 0.3 to 0.7% beryllium, 0.01 to 0.5% zirconium, and a balance of copper.  
     
     
         2 . The copper alloy according to  claim 1 , further comprising 0.005 to 0.2% magnesium.  
     
     
         3 . The copper alloy according to  claim 1 , further comprising 0.005 to 0.2% iron.  
     
     
         4 . The copper alloy according to  claim 2 , further comprising 0.005 to 0.2% iron.  
     
     
         5 . The copper alloy according to  claim 1 , further comprising up to a maximum of 0.15% of at least one element selected from the group consisting of niobium, tantalum, vanadium, hafnium, chromium, manganese, titanium and cerium.  
     
     
         6 . The copper alloy according to  claim 2 , further comprising up to a maximum of 0.15% of at least one element selected from the group consisting of niobium, tantalum, vanadium, hafnium, chromium, manganese, titanium and cerium.  
     
     
         7 . The copper alloy according to  claim 3 , further comprising up to a maximum of 0.15% of at least one element selected from the group consisting of niobium, tantalum, vanadium, hafnium, chromium, manganese, titanium and cerium.  
     
     
         8 . The copper alloy according to  claim 4 , further comprising up to a maximum of 0.15% of at least one element selected from the group consisting of niobium, tantalum, vanadium, hafnium, chromium, manganese, titanium and cerium.  
     
     
         9 . The copper alloy according to  claim 4 , comprising: 1.8 to 2.4% cobalt, 0.45 to 0.65% beryllium, 0.15 to 0.3% zirconium, up to 0.05% magnesium, up to 0.1% iron, and a balance of copper.  
     
     
         10 . The copper alloy according to  claim 1 , wherein up to 80% of the cobalt content is replaced by nickel.  
     
     
         11 . The copper alloy according to  claim 2 , wherein up to 80% of the cobalt content is replaced by nickel.  
     
     
         12 . The copper alloy according to  claim 1 , wherein a part of the zirconium content is replaced by up to 0.15 wt. % of at least one element selected from the group consisting of cerium, hafnium, niobium, tantalum, chromium, manganese, titanium and vanadium.  
     
     
         13 . The copper alloy according to  claim 2 , wherein a part of the zirconium content is replaced by up to 0.15 wt. % of at least one element selected from the group consisting of cerium, hafnium, niobium, tantalum, chromium, manganese, titanium and vanadium.  
     
     
         14 . The copper alloy according to  claim 1 , which, after hot forming of the cast blank, is cold formed up to 40%, is then solution treated at a temperature lying in the temperature range of 850 to 970° C., and is subsequently submitted to a 0.5 to 16-hour age-hardening treatment at 400 to 550° C.  
     
     
         15 . The copper alloy according to  claim 14 , which, after the hot forming, is cold formed by 5 to 30%.  
     
     
         16 . The copper alloy according to  claim 14 , which, after hot forming, is cold formed by 10 to 15%.  
     
     
         17 . The copper alloy according to  claim 1 , which, in the age-hardened state, has a tensile strength of at least 650 Mpa, a Vickers hardness of at least 210 HV, an electrical conductivity of at least 40% IACS, a hot tensile strength at 500° C. of at least 400 Mpa, a minimum hardness of 160 HV after 500 hours of constant ageing at 500° C. and a maximum grain size according to ASTM E112 of 0.5 mm.  
     
     
         18 . The copper alloy according to  claim 1 , which, in the age-hardened state, has a tensile strength of at least 700 to 900 Mpa, a Vickers hardness of 230 to 280 HV, an electrical conductivity of 45 to 60% IACS, a hot tensile strength at 500° C. of at least 450 Mpa and a minimum hardness of 160 HV after 500 hours of constant ageing at 500° C.  
     
     
         19 . The copper alloy according to  claim 1 , which has a grain size between 30 and 90 μm, ascertained according to ASTM E112.