Superalloy compositions, articles, and methods of manufacture

Abstract

A composition of matter comprises, in combination, in weight percent: a largest content of nickel; at least 16.0 percent cobalt; and at least 3.0 percent tantalum. The composition may be used in power metallurgical processes to form turbine engine turbine disks.

1 . A powder metallurgical gas turbine engine disk or disk substrate comprising in combination, in weight percent:
 a content of nickel as a largest content;   at least 18.0 percent cobalt;   at least 6.0 percent tantalum; and   at least 0.5 percent niobium.   
   
   
       2 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 1  wherein:
 said content of nickel is at least 50 percent.   
   
   
       3 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 1  wherein:
 said content of nickel is 44-56 percent.   
   
   
       4 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 1  wherein:
 said content of nickel is 48-52 percent.   
   
   
       5 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 1  further comprising:
 an aluminum content; and   a titanium content, a ratio of said titanium content to said aluminum content being at least 0.57.   
   
   
       6 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 1  further comprising:
 aluminum;   titanium; and   a combined content of said tantalum, aluminum, titanium, and niobium being at least 12.3 percent.   
   
   
       7 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 1  further comprising:
 at least 6.0 percent chromium.   
   
   
       8 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 7  further comprising:
 at least 2.5 percent aluminum; and   no more than 4.0 percent, individually, of every additional constituent, if any.   
   
   
       9 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 7  further comprising:
 at least 5.8% combined of one or more of aluminum, titanium, said niobium, and hafnium.   
   
   
       10 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 7  further comprising:
 at least 6.5% combined of one or more of aluminum, titanium, said niobium, and hafnium.   
   
   
       11 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 1  further comprising:
 at least 2.5 percent aluminum.   
   
   
       12 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 11  further comprising:
 at least 1.5 percent titanium.   
   
   
       13 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 1  further comprising:
 at least 1.5 percent titanium.   
   
   
       14 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 1  further comprising:
 at least 1.5 percent tungsten.   
   
   
       15 . (canceled) 
   
   
       16 . (canceled) 
   
   
       17 . A process for forming the powder metallurgical gas turbine engine disk or disk substrate of  claim 1  comprising:
 compacting a powder having the composition of  claim 1 ;   forging a precursor formed from the compacted powder; and   machining the forged precursor.   
   
   
       18 . The process of  claim 17  further comprising:
 heat treating the precursor, at least one of before and after the machining, by heating to a temperature of no more than 1232° C. (2250° F.)   
   
   
       19 . The process of  claim 17  further comprising:
 heat treating the precursor, at least one of before and after the machining, the heat treating effective to increase a characteristic γ grain size from a first value of about 10 μm or less to a second value of 20-120 μm.   
   
   
       20 . (canceled) 
   
   
       21 . A powder metallurgical gas turbine engine disk or disk substrate comprising in combination, in weight percent:
 a largest content of nickel;   at least 16.0 percent cobalt;   at least 20.0 percent combined cobalt and chromium; and   at least 6.0 percent tantalum.   
   
   
       22 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 21  further comprising:
 at least 5.8% combined of one or more of aluminum, titanium, niobium, and hafnium.   
   
   
       23 . A process for forming powder metallurgical gas turbine engine disk or disk substrate comprising:
 compacting a powder having the composition of  claim 21 ;   forging a precursor formed from the compacted powder; and   machining the forged precursor.   
   
   
       24 . A powder metallurgical gas turbine engine disk or disk substrate comprising in combination, in weight percent:
 from about 18.0 percent to about 21.0 percent cobalt, from about 8.5 percent to about 11.0 percent chromium, from about 6.5 percent to about 8.5 percent tantalum, from about 2.2 percent to about 2.75 percent tungsten, from about 2.5 percent to about 3.4 percent molybdenum, from about 0.03 percent to about 0.07 percent zirconium, from about 0.8 percent to about 2.0 percent niobium, from about 2.0 percent to about 2.75 percent titanium, from about 3.0 percent to about 3.5 percent aluminum, from about 0.02 percent to about 0.07 percent carbon, from about 0.02 percent to about 0.06 percent boron; and   balance nickel and minor amounts of impurities.   
   
   
       25 . (canceled) 
   
   
       26 . (canceled) 
   
   
       27 . A powder metallurgical gas turbine engine disk or disk substrate comprising in combination, in weight percent:
 a content of nickel as a largest content;   at least 16.0 percent cobalt;   at least 26.0 percent combined cobalt and chromium;   at least 3.0 percent tantalum;   at least 0.5 percent niobium;   an aluminum content; and   a titanium content, a ratio of said titanium content to said aluminum content being at least 0.57.   
   
   
       28 . (canceled) 
   
   
       29 . The gas turbine engine disk or disk substrate of  claim 27  being one of:
 an integrally-bladed disk wherein blades are unitarily formed with a disk body; and   a disk having a circumferential array of blade attachment features.   
   
   
       30 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 21  further comprising, by weight:
 3.0-3.5 percent aluminum;   8.5-11.0 percent said chromium;   2.5-3.4 percent molybdenum; and   0.8-2.0 percent niobium.   
   
   
       31 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 30  further comprising, by weight:
 2.0-2.75 percent titanium;   2.2-2.75 percent tungsten; and   0.03-0.07 percent zirconium.   
   
   
       32 . The powder metallurgical gas turbine engine disk or disk substrate of  claim 30  further comprising, by weight up to:
 0.005 percent copper;   0.1 percent iron;   0.5 percent hafnium;   0.005 percent manganese; and   0.1 percent silica.   
   
   
       33 . A powder metallurgical gas turbine engine disk or disk substrate comprising in combination, in weight percent:
 from 18.0 percent to 21.0 percent cobalt, from 8.5 percent to 11.0 percent chromium, from 6.5 percent to 8.5 percent tantalum, from 2.2 percent to 2.75 percent tungsten, from 2.5 percent to 3.4 percent molybdenum, from 0.03 percent to 0.07 percent zirconium, from 0.8 percent to 2.0 percent niobium, from 2.0 percent to 2.75 percent titanium, from 3.0 percent to 3.5 percent aluminum, from 0.02 percent to 0.07 percent carbon, from 0.02 percent to 0.06 percent boron; and   nickel as a largest content.   
   
   
       34 . (canceled) 
   
   
       35 . (canceled) 
   
   
       36 . (canceled)