Thermal barrier coating for reduced sintering and increased impact resistance, and process of making same

Abstract

A composition is disclosed that includes an at least partially stabilized zirconia matrix with a stabilizer and a pentavalent oxide dopant. A coated article is disclosed for use in a high temperature a gas turbine. The coated article can include an yttria-stabilized zirconia, and a pentavalent oxide dopant. The pentavalent oxide dopant can reduce sintering of the thermal barrier coating.

1 . A composition comprising: 
 a ceramic matrix including an at least partially stabilized zirconia and at least one pentavalent oxide dopant in a concentration from about 1 mol percent to about 4 mol percent.    
     
     
         2 . The composition according to  claim 1 , wherein the at least at least one pentavalent oxide dopant is in a concentration from about 1.3 mol percent to about 1.89 mol percent.  
     
     
         3 . The composition according to  claim 1 , wherein the at least at least one pentavalent oxide dopant is in a concentration of about 1.6 mol percent.  
     
     
         4 . The composition according to  claim 1 , wherein the at least partially stabilized zirconia is stabilized from at least one of yttria, calcia, magnesia, ceria, and combinations thereof.  
     
     
         5 . The composition according to  claim 1 , wherein the at least partially stabilized zirconia includes yttria in a range from about 4% to about 8%.  
     
     
         6 . The composition according to  claim 1 , wherein the pentavalent oxide is selected from tantalum oxide, niobium oxide, and combinations thereof.  
     
     
         7 . The composition according to  claim 1 , further including at least one trivalent oxide selected from, lanthanum oxide, ytterbium oxide, gadolinium oxide, neodymium oxide, and combinations thereof.  
     
     
         8 . The composition according to  claim 1 , wherein the pentavalent dopant includes one selected from tantala (Ta 2 O 5 ) and tantalum oxide as a non-stoichiometric solid solution, in a major amount and at least one other pentavalent oxide.  
     
     
         9 . The composition according to  claim 1 , wherein the pentavalent dopant includes one selected from niobia (Nb 2 O 5 ) and niobium oxide as a non-stoichiometric solid solution, in a major amount and at least one other pentavalent oxide.  
     
     
         10 . A coated article, comprising: 
 a superalloy substrate;    a bond coat disposed above the superalloy substrate;    a ceramic interface disposed above the bond coat; and    a thermal barrier coating disposed above the ceramic interface including an yttria-stabilized zirconia (YSZ) and a pentavalent oxide dopant in a concentration from about 1 mol percent to about 4 mol percent.    
     
     
         11 . The coated article according to  claim 10 , wherein the yttrium in the YSZ is about 7%.  
     
     
         12 . The coated article according to  claim 10 , wherein the pentavalent oxide is selected from Ta 2 O 5 , tantalum oxide, Nb 2 O 5 , niobium oxide, and a combination thereof, and wherein the pentavalent oxide is present in a range from about 1.3 mol % to about 1.9 mol %.  
     
     
         13 . The coated article according to  claim 10 , wherein the pentavalent oxide is selected from, tantalum oxide, niobium oxide, and combinations thereof.  
     
     
         14 . The coated article according to  claim 10 , wherein the pentavalent oxide dopant includes one selected from tantala (Ta 2 O 5 ) and tantalum oxide as a non-stoichiometric solid solution, in a major amount and at least one other pentavalent oxide, and wherein the pentavalent oxide dopant is in a concentration range from about 1.2 mol percent to about 2 mol percent.  
     
     
         15 . The coated article according to  claim 10 , wherein the pentavalent oxide dopant includes one selected from niobia (Nb 2 O 5 ) and niobium oxide as a non-stoichiometric solid solution, in a major amount and at least one other pentavalent oxide, and wherein the pentavalent oxide dopant is in a concentration range from about 1.2 mol percent to about 2 mol percent.  
     
     
         16 . A coated turbine blade comprising: 
 a turbine blade substrate including a superalloy;    a turbine blade coating above the turbine blade substrate, wherein the coating is a composition including an yttria-stabilized zirconia (YSZ) matrix and a pentavalent oxide dopant in a concentration from about 1 mol percent to about 4 mol percent.    
     
     
         17 . The coated turbine blade according to  claim 16 , wherein the turbine blade coating includes a bond coat including aluminum, and wherein the pentavalent oxide dopant includes tantala in a range from about 1.3 mol % to about 1.9 mol %.  
     
     
         18 . The coated turbine blade according to  claim 16 , wherein the turbine blade coating includes a bond coat including aluminum, and wherein the pentavalent oxide dopant includes niobia in a range from about 1.3 mol % to about 1.9 mol %.  
     
     
         19 . The coated turbine blade according to  claim 16 , wherein the turbine blade coating includes a bond coat including aluminum, and wherein the pentavalent oxide dopant includes vanadia in a range from about 1.3 mol % to about 1.9 mol %.  
     
     
         20 . A system comprising: 
 a gas turbine, and within the gas turbine a turbine blade, including: 
 a superalloy substrate;  
 a bond coating disposed above the superalloy substrate;  
 a ceramic interface disposed above the bond coating; and  
 a thermal barrier coating disposed above the ceramic interface including an yttria-stabilized zirconia (YSZ) and a pentavalent oxide dopant in a concentration from about 1 mol percent to about 4 mol percent.  
   
     
     
         21 . The system according to  claim 20 , wherein the pentavalent oxide dopant includes from about 1 mol percent to about 2.2 mol percent tantala, niobia, or a combination thereof.