Methods of fabricating and coating turbine components

Abstract

In one aspect, a method of forming a hot gas path component is provided. The method includes forming at least one groove in an outer surface of a substrate, wherein the at least one groove has a base and a top. The method further includes filling the at least one groove with a filler. The method also includes applying at least one cover layer over at least a portion of the outer surface of the substrate such that the at least one groove and the at least one cover layer define at least one micro-channel for cooling the component. The filler is automatically removed from the at least one micro-channel during application of the at least one cover layer. Methods for coating a hot gas component and for assembling a turbine engine assembly are also provided.

What is claimed is: 
     
         1 . A method of forming a hot gas path component, the method comprising:
 forming at least one groove in an outer surface of a substrate, wherein the at least one groove has a base and a top;   filling the at least one groove with a filler; and   applying at least one cover layer over at least a portion of the outer surface of the substrate such that the at least one groove and the at least one cover layer define at least one micro-channel for cooling the component, wherein the filler is automatically removed from the at least one micro-channel during application of the at least one cover layer.   
     
     
         2 . The method in accordance with  claim 1 , wherein forming at least one groove in an outer surface of a substrate comprises forming the base within a range between approximately 0.5 millimeters (mm) and approximately 1.27 mm below the outer surface of the substrate. 
     
     
         3 . The method in accordance with  claim 1 , wherein forming at least one groove in an outer surface of a substrate comprises forming the width of the top within a range between approximately 0.127 mm to approximately 0.4 mm wide. 
     
     
         4 . The method in accordance with  claim 1 , wherein forming at least one groove in an outer surface of a substrate comprises forming the base wider than the top such that the at least one groove forms at least one trapezoidal-shaped shaped groove. 
     
     
         5 . The method in accordance with  claim 4 , wherein the base of the at least one trapezoidal-shaped shaped groove is at least 2 times wider than the top of the at least one trapezoidal-shaped shaped groove. 
     
     
         6 . The method in accordance with  claim 1 , wherein applying at least one cover layer comprises applying the at least one cover layer wherein the at least one cover layer completely bridges the at least one groove such that the at least one cover layer seals the at least one micro-channel. 
     
     
         7 . The method in accordance with  claim 1 , wherein applying at least one cover layer comprises performing at least one of an ion plasma deposition process, a high velocity oxygen fuel (HVOF) spray process, a high velocity air fuel (HVAF) spray process, and a low pressure plasma spray (LPPS) process. 
     
     
         8 . A method of coating a hot gas path component including a substrate, wherein at least one groove is formed in an outer surface of the substrate, the method comprising:
 filling the at least one groove with a filler; and   applying at least one cover layer over at least a portion of the outer surface of the substrate, such that the at least one groove and the at least one cover layer define at least one micro-channel for cooling the component, wherein the filler is automatically removed from the at least one micro-channel during application of the at least one cover layer.   
     
     
         9 . The method in accordance with  claim 8 , wherein applying at least one cover layer comprises applying the at least one cover layer wherein the at least one cover layer completely bridges the at least one groove such that the at least one cover layer seals the at least one micro-channel. 
     
     
         10 . The method in accordance with  claim 8 , wherein applying at least one cover layer comprises performing an ion plasma deposition process. 
     
     
         11 . The method in accordance with  claim 8 , wherein applying at least one cover layer comprises performing a thermal spray process. 
     
     
         12 . The method in accordance with  claim 11 , wherein the thermal spray process is at least one of high velocity oxygen fuel (HVOF) spraying and high velocity air fuel (HVAF) spraying. 
     
     
         13 . The method in accordance with  claim 8 , wherein applying at least one cover layer comprises performing a low pressure plasma spray (LPPS) process. 
     
     
         14 . A method of assembling a turbine engine assembly, said method comprising:
 providing a turbine engine including a compressor, a combustor, and a turbine; and   coupling at least one hot gas path component to the turbine engine, comprising:   forming at least one groove in an outer surface of the hot gas path component;   filling the at least one groove with a filler; and   depositing at least one structural coating over at least a portion of the outer surface of the hot gas path component, such that the at least one groove and the at least one structural coating define at least one micro-channel for cooling the hot gas path component, wherein the filler is automatically removed from the at least one micro-channel during deposition of the at least one structural coating.   
     
     
         15 . The method in accordance with  claim 14 , wherein depositing at least one structural coating comprises depositing at least one of a nickel-based alloy and a cobalt-based alloy. 
     
     
         16 . The method in accordance with  claim 14 , further comprising heat treating the hot gas path component. 
     
     
         17 . The method in accordance with  claim 14 , further comprising applying an oxidation-resistant coating to at least one of the at least one micro-channel and the outer surface of the hot gas path component. 
     
     
         18 . The method in accordance with  claim 14 , wherein forming at least one groove in an outer surface of the hot gas path component comprises forming the at least one groove using at least one of abrasive liquid jet machining, plunge electrochemical machining (ECM), and milling electrical discharge machining (milling EDM). 
     
     
         19 . The method in accordance with  claim 14 , wherein depositing at least one structural coating comprises performing at least of an ion plasma deposition process, a high velocity oxygen fuel (HVOF) spray process, a high velocity air fuel (HVAF) spray process, and a low pressure plasma spray (LPPS) process. 
     
     
         20 . The method in accordance with  claim 14 , wherein depositing at least one structural coating comprises depositing at least one structural coating wherein the at least one structural coating completely bridges the at least one groove such that the at least one structural coating seals the at least one micro-channel.