High temperature thermal barrier coating

Abstract

A high temperature thermal barrier coating which consists of a stabilized ZrO 2 composition for the protection of thermally loaded components ( 10, 10 ′) of a thermal machine, especially a gas turbine, is disclosed. The thermal barrier coating is stabilized with at least 15 mol % Y 1+v Ta 1−v O 4−v , the ZrO 2 is partially substituted by at least 10 mol % HfO 2 and the composition is established according to the formula (Y 1+v Ta 1−v O 4−v ) z (Zr 1−x Hf x O 2 ) 1−z , with x ranging from 0.1 to 0.5, v ranging from −0.1 to 0.2 and z ranging from 0.15 to 0.25.

1 . A high temperature thermal barrier coating for the protection of thermally loaded components of a thermal machine, especially a gas turbine, said thermal barrier coating comprising a stabilized ZrO 2  composition, wherein said composition is stabilized with at least 15 mol % Y 1+v Ta 1−v O 4−v , the ZrO 2  is partially substituted by at least 10 mol % HfO 2  and the composition is established according to the formula
   (Y 1+v Ta 1−v O 4−v ) z (Zr 1−x Hf x O 2 ) 1−z ,   
       with x ranging from 0.1 to 0.5, v ranging from −0.1 to 0.2 and z ranging from 0.15 to 0.25. 
     
     
         2 . The high temperature thermal barrier coating according to  claim 1 , wherein x will range from 0.15 to 0.25, v will range from 0 to 0.1 and z will range from 0.18 to 0.23. 
     
     
         3 . The high temperature thermal barrier coating according to  claim 1 , wherein the high temperature thermal barrier coating covers a component made of a base alloy. 
     
     
         4 . The high temperature thermal barrier coating according to  claim 3 , further comprising a bondcoat provided between the base alloy of the component and the high temperature thermal barrier coating. 
     
     
         5 . The high temperature thermal barrier coating according to  claim 4 , wherein the bondcoat consists of MCrAlYX, where M═Ni, Co or Fe or a mixture thereof and X═Si, Ta, B, Ca or Mg or a mixture thereof, and said bondcoat is deposited by a thermal spray process. 
     
     
         6 . The high temperature thermal barrier coating according to  claim 4 , further comprising an intermediate layer provided between the bondcoat and the high temperature thermal barrier coating. 
     
     
         7 . The high temperature thermal barrier coating according to  claim 6 , wherein the intermediate layer consists of  7 YSZ deposited by a thermal spray process. 
     
     
         8 . The high temperature thermal barrier coating according  claim 1 , wherein the high temperature thermal barrier coating is deposited by a thermal spray process.