Article and method for forming article

Abstract

An article and a method for forming the article are disclosed. The article includes an equiaxed grain structure and a composition. The composition includes, by weight percent, about 6.0% to about 9.0% aluminum, up to about 0.5% titanium, about 2.5% to about 4.5% tantalum, about 10.0% to about 12.5% chromium, about 5.0% to about 10.0% cobalt, about 0.30% to about 0.80% molybdenum, about 2.0% to about 5.0% tungsten, up to about 1.0% silicon, about 0.35% to about 0.60% hafnium, about 0.005% to about 0.010% boron, about 0.06% to about 0.10% carbon, up to about 0.02% zirconium, up to about 0.1% lanthanum, up to about 0.03% yttrium, and balance nickel and incidental impurities. Rhenium, if present, is a trace element. The method for forming the article includes providing the composition having up to about 0.01% rhenium and forming the article.

What is claimed is: 
     
         1 . An article comprising an equiaxed grain structure and a composition, wherein the composition comprises, by weight percent:
 about 6.0% to about 9.0% aluminum (Al);   up to about 0.5% titanium (Ti);   about 2.5% to about 4.5% tantalum (Ta);   about 10.0% to about 12.5% chromium (Cr);   about 5.0% to about 10.0% cobalt (Co);   about 0.30% to about 0.80% molybdenum (Mo);   about 2.0% to about 5.0% tungsten (W);   up to about 1.0% silicon (Si);   about 0.35% to about 0.60% hafnium (Hf);   about 0.005% to about 0.010% boron (B);   about 0.06% to about 0.10% carbon (C);   up to about 0.02% zirconium (Zr);   up to about 0.1% lanthanum (La);   up to about 0.03% yttrium (Y); and   balance nickel (Ni) and incidental impurities, and wherein rhenium (Re), if present, is a trace element.   
     
     
         2 . The article of  claim 1 , wherein the trace element rhenium (Re) is present in an amount of less than about 0.01%, by weight, of the composition. 
     
     
         3 . The article of  claim 1 , wherein the about 2.5% to about 4.5% tantalum (Ta) is replaced completely or partially by niobium (Nb) on a 1:1 molar basis. 
     
     
         4 . The article of  claim 1 , wherein the composition further comprises, by weight percent:
 about 6.2% to about 6.5% aluminum (Al);   up to about 0.04% titanium (Ti);   about 3.9% to about 4.3% tantalum (Ta);   about 12.0% to about 12.5% chromium (Cr);   about 7.0% to about 8.0% cobalt (Co);   about 0.40% to about 0.75% molybdenum (Mo);   about 4.7% to about 5.1% tungsten (W);   about 0.08% to about 0.12% silicon (Si);   about 0.47% to about 0.53% hafnium (Hf);   about 0.005% to about 0.010% boron (B);   about 0.06% to about 0.10% carbon (C);   up to about 0.02% zirconium (Zr);   up to about 0.1% lanthanum (La);   up to about 0.03% yttrium (Y);   up to about 0.01% rhenium (Re); and   balance nickel (Ni); and incidental impurities.   
     
     
         5 . The article of  claim 1 , wherein the article is a hot gas path component of a gas turbine or an aviation engine, and wherein the hot gas path component is subjected to temperatures of at least about 2,000° F. 
     
     
         6 . The article of  claim 5 , wherein the hot gas path component is selected from the group consisting of a blade, a vane, a nozzle, a seal and a stationary shroud. 
     
     
         7 . The article of  claim 1 , wherein the composition is highly castable. 
     
     
         8 . The article of  claim 1 , wherein the composition of the article has an oxidation resistance, the oxidation resistance being about 2 to about 4 times greater than a corresponding oxidation resistance exhibited by a corresponding composition of R108. 
     
     
         9 . The article of  claim 1 , wherein the composition of the article has a low-cycle fatigue lifetime, the low-cycle fatigue lifetime being about 18% to about 22% greater than a corresponding low-cycle fatigue lifetime exhibited by a corresponding composition of N2Re. 
     
     
         10 . The article of  claim 1 , wherein the composition of the article has a creep lifetime, the creep lifetime being about 2.0 to about 2.5 times greater than a corresponding creep lifetime exhibited by a corresponding composition of N2Re. 
     
     
         11 . The article of  claim 1 , wherein the composition of the article has a hot corrosion resistance, the hot corrosion resistance being about 1.5 to about 2.5 times greater than a corresponding hot corrosion resistance exhibited by a corresponding composition of R108. 
     
     
         12 . A method for forming an article, comprising:
 providing a composition comprising, by weight percent:
 about 6.0% to about 9.0% aluminum (Al); 
 up to about 0.5% titanium (Ti); 
 about 2.5% to about 4.5% tantalum (Ta); 
 about 10.0% to about 12.5% chromium (Cr); 
 about 5.0% to about 10.0% cobalt (Co); 
 about 0.30% to about 0.80% molybdenum (Mo); 
 about 2.0% to about 5.0% tungsten (W); 
 up to about 1.0% silicon (Si); 
 about 0.35% to about 0.60% hafnium (Hf); 
 about 0.005% to about 0.010% boron (B); 
 about 0.06% to about 0.10% carbon (C); 
 up to about 0.02% zirconium (Zr); 
 up to about 0.1% lanthanum (La); 
 up to about 0.03% yttrium (Y); 
 up to about 0.01% rhenium (Re); and 
 balance nickel (Ni) and incidental impurities; and 
   forming the article, wherein the article comprises an equiaxed grain structure.   
     
     
         13 . The method of  claim 12 , wherein the about 2.5% to about 4.5% tantalum (Ta) is replaced completely or partially by niobium (Nb) on a 1:1 molar basis. 
     
     
         14 . The method of  claim 12 , wherein the composition further comprises, by weight percent:
 about 6.2% to about 6.5% aluminum (Al);   up to about 0.04% titanium (Ti);   about 3.9% to about 4.3% tantalum (Ta);   about 12.0% to about 12.5% chromium (Cr); about 7.0% to about 8.0% cobalt (Co);   about 0.40% to about 0.75% molybdenum (Mo);   about 4.7% to about 5.1% tungsten (W);   about 0.08% to about 0.12% silicon (Si);   about 0.47% to about 0.53% hafnium (Hf);   about 0.005% to about 0.010% boron (B);   about 0.06% to about 0.10% carbon (C);   up to about 0.02% zirconium (Zr);   up to about 0.1% lanthanum (La);   up to about 0.03% yttrium (Y);   up to about 0.01% rhenium (Re); and   balance nickel (Ni); and incidental impurities.   
     
     
         15 . The method of  claim 12 , wherein the article is a hot gas path component of a gas turbine or an aviation engine, and wherein the hot gas path component is subjected to temperatures of at least about 2,000° F. 
     
     
         16 . The method of  claim 15 , wherein the hot gas path component is selected from the group consisting of a blade, a vane, a nozzle, a seal and a stationary shroud. 
     
     
         17 . The method of  claim 12 , wherein forming the article comprises casting, powder metallurgy or three-dimensional additive machining. 
     
     
         18 . The method of  claim 17 , wherein forming the article comprises casting. 
     
     
         19 . The method of  claim 18 , wherein casting comprises precision investment casting with variable pressure control. 
     
     
         20 . The method of  claim 19 , wherein precision investment casting with variable pressure control comprises:
 a surface re-melting pressure of 10 −3  atmospheres; and   an inert gas casting pressure of about 10 −2  atmospheres to about 10 −1  atmospheres.