Nickel-based alloy

Abstract

The invention provides alloys or superalloys based on nickel essentially comprising the following elements in the amounts indicated as percentages by weight: Cr: 11.5% to 13.5%; Co: 11.5% to 16.0%; Mo: 3.4% to 5.0%; W: 3.0% to 5.0%; Al: 2.2% to 3.2%; Ti: 3.5% to 5.0%; Nb: 0.5% to 2.0%; Hf: 0.25% to 0.35%; Zr: 0 to 0.07%; C: 0.015% to 0.030%; B: 0.01% to 0.02%; and Ni: complement to 100%. The alloy is for use in the production of turbine or compressor disks for turbo-machines, using powder metallurgy techniques.

1 . An alloy essentially comprising the following elements, in the amounts indicated, as percentages by weight: 
 Cr: 11.5% to 13.5%;    Co: 11.5% to 16.0%;    Mo: 3.4% to 5.0%;    W: 3.0% to 5.0%;    Al: 2.2% to 3.2%;    Ti: 3.5% to 5.0%;    Nb: 0.5% to 2.0%;    Hf: 0.25% to 0.35%;    Zr: 0 to 0.07%;    C: 0.015% to 0.030%;    B: 0.01% to 0.02%; and    Ni: complement to 100%.    
     
     
         2 . An alloy according to  claim 1 , wherein the sum of the amounts of Al, Ti, and Nb, as an atomic percentage, is 10.5% or more and 13% or less.  
     
     
         3 . An alloy according to  claim 1 , wherein the amounts of Al, Ti, and Nb, as an atomic percentage, are such that the ratio between the sum of the amounts of Ti and Nb, and the amount of Al, is 0.9 or more and 1.1 or less.  
     
     
         4 . An alloy according to  claim 2 , wherein the amounts of Al, Ti, and Nb, as an atomic percentage, are such that the ratio between the sum of the amounts of Ti and Nb, and the amount of Al, is 0.9 or more and 1.1 or less.  
     
     
         5 . An alloy according to  claim 1 , wherein the amounts of W, Mo, Cr, and Co, as atomic percentages, is such that the sum of the amounts of W, Mo, Cr, and Co is 30% or more and 34% or less, and such that the sum of the amounts of W and Mo is 3% or more and 4.5% or less.  
     
     
         6 . An alloy according to  claim 2 , wherein the amounts of W, Mo, Cr, and Co, as atomic percentages, is such that the sum of the amounts of W, Mo, Cr, and Co is 30% or more and 34% or less, and such that the sum of the amounts of W and Mo is 3% or more and 4.5% or less.  
     
     
         7 . An alloy according to  claim 3 , wherein the amounts of W, Mo, Cr, and Co, as atomic percentages, is such that the sum of the amounts of W, Mo, Cr, and Co is 30% or more and 34% or less, and such that the sum of the amounts of W and Mo is 3% or more and 4.5% or less.  
     
     
         8 . An alloy according to  claim 4 , wherein the amounts of W, Mo, Cr, and Co, as atomic percentages, is such that the sum of the amounts of W, Mo, Cr, and Co is 30% or more and 34% or less, and such that the sum of the amounts of W and Mo is 3% or more and 4.5% or less.  
     
     
         9 . A powder of an alloy according to  claim 1 .  
     
     
         10 . A method of fabricating a part, wherein a blank of said part or the part itself is produced from a powder of an alloy according to  claim 1 , using a powder metallurgy technique.  
     
     
         11 . A method of fabricating a part according to  claim 10 , wherein said blank or said part undergoes a recrystallization heat treatment in which the blank or the part is brought to a temperature which is higher than the solvus temperature of the gamma-prime phase of said alloy and lower than the melting onset temperature for said alloy.  
     
     
         12 . A method of fabricating a part according to  claim 10 , wherein said blank or said part undergoes a recrystallization heat treatment in which the blank or the part is brought to a temperature which is lower than the solvus temperature of the gamma-prime phase of said alloy.  
     
     
         13 . A method of fabricating a part, wherein a blank of said part or the part itself is produced from a powder of an alloy according to  claim 8 , using a powder metallurgy technique.  
     
     
         14 . A method of fabricating a part according to  claim 13 , wherein said blank or said part undergoes a recrystallization heat treatment in which the blank or the part is brought to a temperature which is higher than the solvus temperature of the gamma-prime phase of said alloy and lower than the melting onset temperature for said alloy.  
     
     
         15 . A method of fabricating a part according to  claim 13 , wherein said blank or said part undergoes a recrystallization heat treatment in which the blank or the part is brought to a temperature which is lower than the solvus temperature of the gamma-prime phase of said alloy.  
     
     
         16 . A turbo-machine part produced from an alloy according to  claim 1 .  
     
     
         17 . A turbo-machine part according to  claim 16 , having a coarse-grained structure in the zone in which it is subjected to the highest operational temperatures and where creep plays a significant role in damage to the part, and a small-grained structure in the zone in which it is subjected to the lowest operational temperatures and where damage essentially results from tensile forces and cyclic stresses.  
     
     
         18 . A turbo-machine part according to  claim 17 , consisting of a compressor or turbine disk.  
     
     
         19 . A turbo-machine part produced from an alloy according to  claim 8 .  
     
     
         20 . A turbo-machine part according to  claim 19 , having a coarse-grained structure in the zone in which it is subjected to the highest operational temperatures and where creep plays a significant role in damage to the part, and a small-grained structure in the zone in which it is subjected to the lowest operational temperatures and where damage essentially results from tensile forces and cyclic stresses.  
     
     
         21 . A turbo-machine part according to  claim 20 , consisting of a compressor or turbine disk.