Superalloy compositions with improved oxidation performance and gas turbine components made therefrom

Abstract

Single crystal superalloy compositions and components made from such compositions are provided. One composition consists essentially of, in weight percent, from about 4 to about 7 percent chromium; from about 8 to about 12 percent cobalt; from about 1 to about 2.5 percent molybdenum; from about 3 to about 6 percent tungsten; from about 2 to about 4 percent rhenium; from about 5 to about 7 percent aluminum; from about 0 to about 1.5 percent titanium; from about 6 to about 10 percent tantalum; from about 0.08 to about 1.2 percent hafnium; no more than about 0.0002 percent sulfur; no more than about 0.007 percent zirconium; and the balance nickel.

1 . A single crystal nickel-based superalloy composition consisting essentially of, in weight percent:
 from about 4 to about 7 percent chromium;   from about 8 to about 12 percent cobalt;   from about 1 to about 2.5 percent molybdenum;   from about 3 to about 6 percent tungsten;   from about 2 to about 4 percent rhenium;   from about 5 to about 7 percent aluminum;   from about 0 to about 1.5 percent titanium;   from about 6 to about 10 percent tantalum;   from about 0.08 to about 1.2 percent hafnium;   no more than about 0.0002 percent sulfur;   no more than about 0.007 percent zirconium; and   the balance nickel.   
   
   
       2 . The single crystal nickel-based superalloy composition of  claim 1 , further consisting essentially of (in weight percent) from about 0.001 to about 0.015 weight percent of one selected from the group consisting of yttrium, lanthanum, cerium, and a combination thereof. 
   
   
       3 . The single crystal nickel-based superalloy composition of  claim 2 , further consisting essentially of (in weight percent) from about 0.03 to about 0.10 percent carbon and from about 0.003 to about 0.006 percent boron. 
   
   
       4 . The single crystal nickel-based superalloy composition of  claim 1 , wherein a sum of the molybdenum, tungsten, and rhenium is from about 8.4 to about 10.4 weight percent. 
   
   
       5 . The single crystal nickel-based superalloy composition of  claim 1 , wherein a sum of aluminum, titanium, and tantalum is about 13.8 to about 15.7 weight percent. 
   
   
       6 . The single crystal nickel-based superalloy composition of  claim 1 , wherein the percentage of hafnium is from about 0.08 to about 0.12 weight percent. 
   
   
       7 . The single crystal nickel-based superalloy composition of  claim 1 , wherein the percentage of hafnium is from about 0.15 to about 1.2 weight percent. 
   
   
       8 . A single crystal nickel-based superalloy component fabricated of a single crystal composition consisting essentially of (in weight percent):
 from about 4 to about 7 percent chromium;   from about 8 to about 12 percent cobalt;   from about 1 to about 2.5 percent molybdenum;   from about 3 to about 6 percent tungsten;   from about 2 to about 4 percent rhenium;   from about 5 to about 7 percent aluminum;   from about 0 to about 1.5 percent titanium;   from about 6 to about 10 percent tantalum;   from about 0.08 to about 1.2 percent hafnium;   no more than about 0.0002 percent sulfur;   no more than about 0.007 percent zirconium; and   the balance nickel.   
   
   
       9 . The single crystal nickel-based superalloy component of  claim 8 , wherein the single crystal nickel-based superalloy component is a turbine blade. 
   
   
       10 . The single crystal nickel-based superalloy component of  claim 8 , wherein the single crystal nickel-based superalloy component is a vane. 
   
   
       11 . The single crystal nickel-based superalloy component of  claim 8 , further consisting essentially of (in weight percent) from about 0.001 to about 0.015 weight percent of one selected from the group consisting of yttrium, lanthanum, cerium, and a combination thereof. 
   
   
       12 . The single crystal nickel-based superalloy component of  claim 10 , further consisting essentially of (in weight percent) from about 0.03 to about 0.10 percent carbon and from about 0.003 to about 0.006 percent boron. 
   
   
       13 . The single crystal nickel-based superalloy component of  claim 8 , wherein the percentage of hafnium is from about 0.08 to about 0.12 percent. 
   
   
       14 . The single crystal nickel-based superalloy component of  claim 8 , wherein the percentage of hafnium is from about 0.15 to about 1.2 percent. 
   
   
       15 . A process for preparing a single crystal nickel-based superalloy component, the method comprising the steps of:
 providing an alloy comprising (in weight percent):   from about 4 to about 7 percent chromium;   from about 8 to about 12 percent cobalt;   from about 1 to about 2.5 percent molybdenum;   from about 3 to about 6 percent tungsten;   from about 2 to about 4 percent rhenium;   from about 5 to about 7 percent aluminum;   from about 0 to about 1.5 percent titanium;   from about 6 to about 10 percent tantalum;   from about 0.08 to about 1.2 percent hafnium;   no more than about 0.0002 percent sulfur;   no more than about 0.007 percent zirconium; and   the balance nickel; and   fabricating a single crystal component from the alloy.   
   
   
       16 . The process of  claim 15 , wherein the step of providing an alloy comprises the step of providing an alloy further comprising (in weight percent) from about 0.001 to about 0.015 weight percent of one selected from the group consisting of yttrium, lanthanum, cerium, and a combination thereof. 
   
   
       17 . The process of  claim 16 , wherein the step of providing an alloy comprises the step of providing an alloy further comprising (in weight percent) from about 0.03 to about 0.10 percent carbon and from about 0.003 to about 0.006 percent boron. 
   
   
       18 . The process of  claim 15 , wherein the step of fabricating a single crystal component from the alloy comprises the step of fabricating a turbine blade and a vane from the alloy.