Methods for fabricating turbine engine components

Abstract

Methods are provided that include depositing a nickel-base superalloy powder including gamma nickel solid solution and gamma prime (Ni3Al) solid solution phases onto a seed crystal having a predetermined primary orientation, fully melting the powder and a portion of the seed crystal at a superliquidus temperature to form an initial layer having the predetermined primary orientation, heat treating the layer at subsolvus temperatures to precipitate gamma prime solid solution phase particles, depositing additional powder over the layer, melting the deposited powder and a portion of the initial layer at a superliquidus temperature to form a successive layer having the predetermined primary orientation, heat treating the layer at a subsolvus temperature to precipitate gamma prime solid solution phase particles, and repeating depositing additional powder, melting the additional powder and the portion of the successive layer at the superliquidus temperature, and heat treating the successive layer at a subsolvus temperature.

What is claimed is: 
     
         1 . An additive manufactured directionally solidified or single crystal nickel-based superalloy turbine component comprising:
 a first layer that has a predetermined primary crystallographic orientation of a superalloy seed crystal, the first layer comprising a few percent of a gamma prime solid solution phase as precipitated particles within a supersaturated gamma phase; and   at least one additional layer on the first layer, the at least one additional layer having the predetermined primary orientation and a few percent of the gamma prime solid solution phase as particles within the supersaturated gamma phase.   
     
     
         2 . The nickel-based superalloy turbine engine component of  claim 1 , wherein the nickel-based superalloy has a composition that comprises 50% to about 70% gamma prime solid solution phase by volume. 
     
     
         3 . The article of  claim 1 , wherein the volume fraction of gamma prime solid solution phase precipitates within the supersaturated gamma phase is increased and optimized by post-fabrication heat treatment. 
     
     
         4 . The nickel-based superalloy turbine engine component of  claim 1 , wherein the first layer has a thickness from about 15 microns to about 50 microns. 
     
     
         5 . The nickel-based superalloy turbine engine component of  claim 1 , wherein the at least one additional layer has a thickness from about 15 microns to about 50 microns. 
     
     
         6 . The nickel-based superalloy turbine engine component of  claim 1 , wherein the seed crystal comprises a single crystal superalloy seed having a predetermined secondary orientation that is orthogonal relative to the predetermined primary orientation. 
     
     
         7 . The nickel-based superalloy turbine engine component of  claim 1 , wherein a surface of the nickel-based superalloy turbine engine component has been treated by vibratory surface finishing, abrasive flow machining, or chemical surface finishing. 
     
     
         8 . The nickel-based superalloy turbine engine component of  claim 7 , wherein the vibratory surface finishing, abrasive flow machining, or chemical surface finishing removes up to 30 microns of the surface of the nickel-based superalloy turbine engine component. 
     
     
         9 . The nickel-based superalloy turbine engine component of  claim 1 , further comprising a coating over a surface of the nickel-based superalloy turbine engine component. 
     
     
         10 . The nickel-based superalloy turbine engine component of  claim 1 , wherein the few percent of the gamma prime solid solution phase particles precipitated within the supersaturated gamma phase is 1 to 5 percent.