Nickel base superalloy

Abstract

A nickel base superalloy consisting of 20 to 40 wt % cobalt, 10 to 15 wt % chromium, 3 to 6 wt % molybdenum, 0 to 5 wt % tungsten, 2.5 to 4 wt % aluminium, 3.4 to 5 wt % titanium, 1.35 to 2.5 wt % tantalum, 0 to 2 wt % niobium, 0.5 to 1 wt % hafnium, 0 to 0.1 wt % zirconium, 0.01 to 0.05 wt % carbon, 0.01 to 0.05 wt % boron, 0 to 2 wt % silicon and the balance nickel plus incidental impurities. The gamma prime phase comprises (Ni/Co) 3 (Al/Ti/Ta).

1 . A nickel base superalloy consisting of 23 to 40 wt % cobalt, 10 to 15 wt % chromium, 3 to 6 wt % molybdenum, 0 to 5 wt % tungsten, 2.5 to 4 wt % aluminium, 3.4 to 5 wt % titanium, 1.35 to 2.5 wt % tantalum, 0 to 2 wt % niobium, 0.5 to 1 wt % hafnium, 0 to 0.1 wt % zirconium, 0.01 to 0.05 wt % carbon, 0.01 to 0.05 wt % boron, 0 to 2 wt % silicon and the balance nickel plus incidental impurities. 
     
     
         2 . A nickel base superalloy as claimed in  claim 1  consisting of 23.5 to 30 wt % cobalt, 10 to 15 wt % chromium, 3 to 6 wt % molybdenum, 0 to 5 wt % tungsten, 2.5 to 4 wt % aluminium, 3.4 to 5 wt % titanium, 1.35 to 2.5 wt % tantalum, 0 to 2 wt % niobium, 0.5 to 1 wt % hafnium, 0 to 0.1 wt % zirconium, 0.01 to 0.05 wt % carbon, 0.01 to 0.05 wt % boron, 0 to 1 wt % silicon and the balance nickel plus incidental impurities. 
     
     
         3 . A nickel base superalloy as claimed in  claim 1  consisting of 23.5 to 28 wt % cobalt, 10 to 15 wt % chromium, 3 to 6 wt % molybdenum, 0 to 5 wt % tungsten, 2.5 to 4 wt % aluminium, 3.4 to 5 wt % titanium, 1.35 to 2.5 wt % tantalum, 0.5 to 1 wt % hafnium, 0 to 0.1 wt % zirconium, 0.01 to 0.05 wt % carbon, 0.01 to 0.05 wt % boron, 0 to 0.2 wt % silicon and the balance nickel plus incidental impurities. 
     
     
         4 . A nickel base superalloy as claimed in  claim 3  consisting of 24 to 27 wt % cobalt, 14.5 wt % chromium, 5 wt % molybdenum, 3 wt % aluminium, 4.5 wt % titanium, 2 wt % tantalum, 0.55 wt % hafnium, 0.06 wt % zirconium, 0.027 to 0.03 wt % carbon, 0.015 to 0.02 wt % boron, 0 to 0.2 wt % silicon and the balance nickel plus incidental impurities. 
     
     
         5 . A nickel base superalloy as claimed in  claim 1  consisting of 24 to 27 wt % cobalt, 10 to 15 wt % chromium, 3 to 6 wt % molybdenum, 0 to 5 wt % tungsten, 2.5 to 4 wt % aluminium, 3.4 to 5 wt % titanium, 1.35 to 2.5 wt % tantalum, 0.5 to 1 wt % hafnium, 0 to 0.1 wt % zirconium, 0.01 to 0.05 wt % carbon, 0.01 to 0.05 wt % boron, 0 to 0.2 wt % silicon and the balance nickel plus incidental impurities. 
     
     
         6 . A nickel base superalloy as claimed in  claim 1  wherein the precipitated gamma prime phase comprises a (Ni/Co) 3  (Al/Ti/Ta). 
     
     
         7 . A nickel base superalloy as claimed in  claim 1  wherein the precipitated gamma prime phase comprises a (Ni/Co) 3  (Al/Ti/Ta/Nb). 
     
     
         8 . A nickel base superalloy as claimed in  claim 1  wherein the precipitated gamma prime phases comprises Co 3 Ta and/or Co 3 Ti. 
     
     
         9 . A gas turbine engine component comprising a nickel base superalloy as claimed in  claim 1 . 
     
     
         10 . A gas turbine engine component as claimed in  claim 9  wherein the component is a turbine disc or a compressor disc. 
     
     
         11 . A nickel base superalloy as claimed in  claim 1 , wherein the nickel base superalloy has a fine grain size, the fine grain size being 5 to 10 micrometers. 
     
     
         12 . A nickel base superalloy as claimed in  claim 1 , wherein the nickel base superalloy has a coarse grain size, the coarse grain size being greater than 30 micrometers. 
     
     
         13 . A method of producing a nickel base superalloy consisting of 23 to 40 wt % cobalt, 10 to 15 wt % chromium, 3 to 6 wt % molybdenum, 0 to 5 wt % tungsten, 2.5 to 4 wt % aluminium, 3.4 to 5 wt % titanium, 1.35 to 2.5 wt % tantalum, 0 to 2 wt % niobium, 0.5 to 1 wt % hafnium, 0 to 0.1 wt % zirconium, 0.01 to 0.05 wt % carbon, 0.01 to 0.05 wt % boron, 0 to 2 wt % silicon and the balance nickel plus incidental impurities, by processing the nickel base superalloy by powder metallurgy. 
     
     
         14 . A method as claimed in  claim 13  comprising processing the nickel base superalloy at a temperature above the gamma prime solvus temperature. 
     
     
         15 . A method as claimed in  claim 13  comprising processing the nickel base superalloy at a temperature below the gamma prime solvus temperature. 
     
     
         16 . A method as claimed in  claim 13  comprising producing a fine grain size in the nickel base superalloy, the fine grain size being 5 to 10 micrometers. 
     
     
         17 . A method as claimed in  claim 13  comprising producing a coarse grain size in the nickel base superalloy, the coarse grain size being greater than 30 micrometers.