Powder metal mold

Abstract

Described is a process of producing a component from a gamma prime or gamma double prime precipitation-strengthened nickel-base superalloy. The process includes forming a powder of the superalloy and filling a can with the powder wherein the can includes nickel-chromium-molybdenum-niobium alloy. The can is evacuated and sealed in a controlled environment. The can and the powder are consolidated at a temperature, time, and pressure to produce a consolidation. The consolidated billet is forged at a temperature and strain rate to produce a forging with a uniform fine grain throughout. A further aspect described is a mold including a nickel-chromium-molybdenum-niobium alloy can.

1 . A process of producing a component from a gamma prime or gamma double prime precipitation-strengthened nickel-base superalloy, the process comprising:
 forming a powder of the superalloy;   filling a can with the powder wherein the can comprises nickel-chromium-molybdenum-niobium alloy;   evacuating and sealing the can in a controlled environment;   consolidating the can and the powder therein at a temperature, time, and pressure to produce a billet; and   forging the billet at a temperature and strain rate to produce a forging.   
     
     
         2 . A process according to  claim 1 , wherein the nickel-base superalloy has a composition of, by weight, about 19 to about 23% chromium, about 7 to about 8% molybdenum, about 3 to about 4% niobium, about 4 to about 6% iron, about 0.3 to about 0.6% aluminum, about 1 to about 1.8% titanium, about 0.002 to about 0.004% boron, about 0.35% maximum manganese, about 0.2% maximum silicon, about 0.03% maximum carbon, a balance of nickel and incidental impurities. 
     
     
         3 . A process according to  claim 1 , wherein the nickel-chromium-molybdenum-niobium alloy has a composition of, by weight, about 55.0 to about 59.0% nickel, about 19.0 to about 22.5% chromium, about 7.0 to about 9.5% molybdenum, about 2.75 to about 4.00% niobium, about 1.0 to about 1.7% titanium, about 0.35% maximum aluminum, about 0.03% maximum carbon, about 0.35% maximum manganese, about 0.20% maximum silicon, about 0.015% phosphorous, about 0.010% maximum sulfur, a balance of iron and incidental impurities. 
     
     
         4 . A process according to  claim 1 , wherein the billet formed by the consolidation step has a density of at least 99.9% of theoretical. 
     
     
         5 . A process according to  claim 1 , wherein the component is a rotor component of a gas turbine engine. 
     
     
         6 . A process according to  claim 5 , wherein the billet weighs about 1.8 to about 4 times the weight of the component. 
     
     
         7 . A process according to  claim 1 , further comprising solution heat treating the forging. 
     
     
         8 . A process according to  claim 7 , wherein the solution heat treating comprises:
 solution heat treatment at a temperature of about 900° C. for approximately four hours;   aging at a temperature of about 760° C. for approximately eight hours;   cooling at a rate of about 56° C. per minute to about 620° C.;   holding for approximately eight hours; and   air cooling.   
     
     
         9 . A process according to  claim 1 , further comprising machining the forging. 
     
     
         10 . A process according to  claim 1 , wherein the billet has a grain size of no larger than about ASTM 8. 
     
     
         11 . A process according to  claim 1 , further comprising ultrasonic testing of the forging. 
     
     
         12 . A process according to  claim 1 , further comprising ultrasonic testing of the billet. 
     
     
         13 . A mold comprising:
 a nickel-chromium-molybdenum-niobium alloy can.   
     
     
         14 . The mold of  claim 13 , wherein the nickel-chromium-molybdenum-niobium alloy has a composition of, by weight, about 55.0 to about 59.0% nickel, about 19.0 to about 22.5% chromium, about 7.0 to about 9.5% molybdenum, about 2.75 to about 4.00% niobium, about 1.0 to about 1.7% titanium, about 0.35% maximum aluminum, about 0.03% maximum carbon, about 0.35% maximum manganese, about 0.20% maximum silicon, about 0.015% phosphorous, about 0.010% maximum sulfur, a balance of iron and incidental impurities. 
     
     
         15 . The mold of  claim 13  wherein sides of the can are substantially square.