Protective coating systems for gas turbine engine applications and methods for fabricating the same

Abstract

Protective coating systems for gas turbine engine applications and methods for fabricating such protective coating systems are provided. An exemplary protective coating system comprises an aluminide-comprising bond coating disposed on a substrate, a thermal barrier coating overlying the aluminide-comprising bond coating, and a silicate layer interposed between the thermal barrier coating and the aluminide-comprising bond coating.

1 . A protective coating system for a substrate, the protective coating system comprising:
 an aluminide-comprising bond coating disposed on the substrate;   a thermal barrier coating overlying the aluminide-comprising bond coating; and   a silicate layer interposed between the thermal barrier coating and the aluminide-comprising bond coating.   
     
     
         2 . The protective coating system of  claim 1 , wherein the substrate comprises a material selected from the group consisting of nickel-based superalloys, cobalt-based superalloys, titanium-based superalloys, nickel aluminides, alumina fiber/alumina silicate matrix composites, silicon carbide fiber/silicon carbide matrix composites, alumina fiber/refractory metal matrix composites, alumina fiber/MCrAlY matrix composites, refractory metal fiber/MCrAlY matrix composites, alumina fiber/NiAl matrix composites, silicon carbide fiber/gamma TiAl matrix composites, refractory metal fiber/NiAl matrix composites, carbon fiber/carbon matrix composites, alumina fiber/TiAl alloy matrix composites, silicon carbide fiber/alumna matrix composites, and silicon carbide fiber/silicon nitride matrix composites. 
     
     
         3 . The protective coating system of  claim 1 , wherein the aluminide-comprising bond coating comprises an additional non-aluminide metal layer 
     
     
         4 . The protective coating system of  claim 3 , wherein the additional non-aluminide metal layer is a platinum layer. 
     
     
         5 . The protective coating system of  claim 1 , wherein the aluminide-comprising bond coating comprises MAlX, wherein M is cobalt, iron, nickel, a combination thereof, diffusion aluminide, platinum aluminide, or an active element-modified aluminide and X is hafnium, zirconium, yttrium, tantalum, rhenium ruthenium, palladium, platinum, silicon, titanium, boron, carbon, or combinations thereof. 
     
     
         6 . The protective coating system of  claim 5 , wherein the aluminide-comprising bond coating comprises NiAlZr. 
     
     
         7 . The protective coating system of  claim 5 , wherein MAlX comprises chromium. 
     
     
         8 . The protective coating system of  claim 7 , wherein the aluminide-comprising bond coating comprises NiAlCrZr. 
     
     
         9 . The protective coating system of  claim 1 , wherein the thermal barrier coating comprises a stabilized hafnia-based thermal barrier coating. 
     
     
         10 . The protective coating system of  claim 1 , wherein the thermal barrier coating comprises stabilized zirconia. 
     
     
         11 . The protective coating system of  claim 10 , wherein the thermal barrier coating comprises yttria stabilized zirconia. 
     
     
         12 . The protective coating system of  claim 1 , wherein the thermal barrier coating comprises stabilized hafnia. 
     
     
         13 . The protective coating system of  claim 12 , wherein the thermal barrier coating comprises yttria stabilized hafnia. 
     
     
         14 . The protective coating system of  claim 1 , wherein the silicate layer comprises silicon dioxide or zirconium silicate. 
     
     
         15 . The protective coating system of  claim 14 , wherein the silicate layer further comprises zirconium oxide (Zr 2 O 3 ). 
     
     
         16 . The protective coating system of  claim 1 , wherein the silicate layer comprises silica and zirconium oxide (Zr 2 O 3 ) layers. 
     
     
         17 . The protective coating system of  claim 1 , wherein the silicate layer comprises mixed silica and zirconium oxide (Zr 2 O 3 ) in a ratio of about 0.3 to about 0.7.