Atomic layer deposition for turbine components

Abstract

A method and superalloy component for depositing a layer of material onto gas turbine engine components by atomic layer deposition. A superalloy component may have a ceramic thermal barrier coating on at least a portion of its surface, comprising a superalloy substrate and a bonding coat; and aluminum oxide (Al 2 O 3 ) layer may be deposited on top of an yttria-stabilized zirconia layer and form a bonding coat by atomic layer deposition. The yttria-stabilized zirconia layer may have a plurality of micron sized gaps extending from the top surface of the ceramic coating towards the substrate and defining a plurality of columns of the yttria-stabilized zirconia layer. Also, atomic layer deposition may be used to lay an aluminum oxide (Al 2 O 3 ) layer over a tantalum oxide (Ta 2 O 5 ) layer on a silicon-based substrate. Using atomic layer deposition to coat the gas turbine engine components permits conformal coating of the columnar surface to permit gap expansion and contraction without sintering of the columnar surface or spalling of the coating, and form an oxidation resistant bonding coat.

1 . A superalloy component having a ceramic thermal barrier coating on at least a portion of its surface, comprising:
 a superalloy substrate;   a ceramic coating overlying the superalloy substrate, the ceramic coating having a plurality of gaps between a plurality of columns; and   an inorganic layer overlying the ceramic coating and conformally coating the plurality of gaps; wherein the inorganic layer is deposited over the ceramic coating by atomic layer deposition.   
   
   
       2 . The superalloy component of  claim 1 , further comprising a bonding coat located between the superalloy substrate and the ceramic coating; wherein the bonding coat is deposited over the superalloy substrate by atomic layer deposition. 
   
   
       3 . The superalloy component of  claim 1 , wherein the plurality of gaps are micron sized gaps. 
   
   
       4 . The superalloy component of  claim 1 , wherein the plurality of gaps are sub-micron sized gaps. 
   
   
       5 . The superalloy component of  claim 1 , wherein the ceramic coating comprises yttria-stabilized zirconia. 
   
   
       6 . The superalloy component of  claim 1 , wherein the ceramic coating comprises tantalum oxide (Ta.sub.2O.sub.5). 
   
   
       7 . The superalloy component of  claim 1 , wherein the inorganic layer comprises a substance selected from the group consisting of oxides, nitrides, metal films, metal alloy films, and nano-laminates thereof. 
   
   
       8 . The superalloy component of  claim 1 , wherein the inorganic layer comprises a compound of Al, Hf, Si, Ln (rare earth including entire lanthanum series, scandium and yttrium), Mg, Mo, Ni, Nb, Sr, or Ti. 
   
   
       9 . The superalloy component of  claim 8 , wherein the inorganic layer comprises a substance selected from the group consisting of aluminum oxide (Al.sub.2O.sub.3), tantalum oxide (Ta.sub.2O.sub.5), hafnium oxide (HfO.sub.2), mixtures thereof, and nano-laminates thereof. 
   
   
       10 . A superalloy component having a ceramic thermal barrier coating on at least a portion of its surface, comprising:
 a superalloy substrate;   an yttria-stabilized zirconia layer overlying the superalloy substrate, the yttria-stabilized zirconia layer having a plurality of gaps between a plurality of columns; and an aluminum oxide (Al.sub.2O.sub.3) layer overlying the yttria-stabilized zirconia layer, conformally coating the plurality of gaps;   wherein the aluminum oxide (Al.sub.2O.sub.3) layer is deposited over the yttria-stabilized zirconia layer by atomic layer deposition.   
   
   
       11 . The superalloy component of  claim 10 , further comprising a bonding coat located between the superalloy substrate and the yttria-stabilized zirconia layer; wherein the bonding coat is deposited over the superalloy substrate by atomic layer deposition. 
   
   
       12 . The superalloy component of  claim 10 , wherein the plurality of gaps are micron sized gaps. 
   
   
       13 . The superalloy component of  claim 10 , wherein the plurality of gaps are sub-micron sized gaps. 
   
   
       14 . The superalloy component of  claim 10 , wherein the ceramic coating comprises yttria-stabilized zirconia. 
   
   
       15 . The superalloy component of  claim 10 , wherein the inorganic layer comprises a substance selected from the group—consisting of oxides, nitrides, metal films, metal alloy films, and nano-laminates thereof. 
   
   
       16 . The superalloy component of  claim 10 , wherein the inorganic layer comprises a compound of Al, Hf, Si, Ln (rare earth including entire lanthanum series, scandium and yttrium) Mg, Mo, Ni, Nb, Sr, or Ti. 
   
   
       17 . The superalloy component of  claim 16 , wherein the inorganic layer comprises a substance selected from the group consisting of aluminum oxide (Al.sub.2O.sub.3), tantalum oxide (Ta.sub.2O.sub.5), hafnium oxide (HfO.sub.2), alloys thereof, and nano-laminates thereof. 
   
   
       18 . A component having a ceramic environmental barrier coating on at least a portion of its surface, comprising:
 a silicon-based substrate;   a tantalum oxide (Ta.sub.2O.sub.5) layer overlying the silicon-based substrate having a plurality of gaps between a plurality of columns; and an aluminum oxide (Al.sub.2O.sub.3) layer overlying the tantalum oxide (Ta.sub.2O.sub.5) layer, conformally coating the plurality of gaps;   wherein the aluminum oxide (Al.sub.2Osub.3) layer is deposited over the tantalum oxide (Ta.sub.2O.sub.5) layer by atomic layer deposition.   
   
   
       19 . The component of  claim 18 , further comprising a bonding coat located between the silicon-based substrate and the tantalum oxide (Ta.sub.2O.sub.5) layer; wherein the bonding coat is deposited over the silicon-based substrate by atomic layer deposition. 
   
   
       20 . The component of  claim 18 , wherein the plurality of gaps are micron sized gaps. 
   
   
       21 . The component of  claim 18 , wherein the plurality of gaps are sub-micron sized gaps. 
   
   
       22 . The component of  claim 18 , wherein the plurality of micron sized gaps extend from the top surface of the tantalum oxide (Ta.sub.2O.sub.5) layer towards the silicon-based substrate. 
   
   
       23 . The component of  claim 18 , wherein the ceramic environmental barrier coating has a thickness of about 0.05 mm to about 1.3 mm. 
   
   
       24 . The component of  claim 18 , wherein the aluminum oxide (Al.sub.2O.sub.3) layer is at a thickness in the range of about 5 nm to about 5,000 nm 
   
   
       25 . The component of  claim 24 , wherein the aluminum oxide (Al.sub.2O.sub.3) layer is at a thickness in the range of about 5 nm to about 2,500 nm.