Thermal barrier for turbine blades, having a columnar structure with spaced-apart columns

Abstract

A process for depositing a ceramic layer on a metal substrate for producing a thermal barrier, the process including depositing the ceramic in a columnar structure. The deposition is carried out through a grid pierced with holes, which is positioned parallel to a surface of the substrate so as to produce ceramic columns separated from one another by a space. The process can further include a subsequent depositing of an isotropic ceramic layer in the spaces.

1 - 12 . (canceled) 
     
     
         13 . A process for depositing a ceramic layer onto a metallic substrate for producing a thermal barrier, comprising:
 depositing the ceramic in a columnar structure, the depositing taking place through a grid pierced with holes, positioned parallel to a surface of the substrate so as to produce at least two columns of ceramic that are separated from one another by a spacing; and   a subsequent depositing an isotropic layer of ceramic in the spacings.   
     
     
         14 . The process as claimed in  claim 13 , wherein a width of the holes is between 10 and 300 microns. 
     
     
         15 . The process as claimed in  claim 13 , wherein the spacing between the holes is between 10 and 100 microns. 
     
     
         16 . The process as claimed in  claim 13 , wherein the second depositing is carried out by an operation for dip-coating the substrate including its columns into a solution of sol-gel type. 
     
     
         17 . The process as claimed in  claim 16 , wherein the isotropic depositing is carried out by a sequence of dip-coating and withdrawal operations in the sol-gel solution and drying operations carried out between two dip-coating and withdrawal operations, until a thickness substantially equal to a height of the columns is obtained. 
     
     
         18 . The process as claimed in  claim 13 , further comprising a heat treatment. 
     
     
         19 . A thermal barrier deposited on a metallic substrate, comprising:
 ceramic columns that extend perpendicular to a surface of the substrate and that are separated from one another by spacings, the spacings being filled with an isotropic ceramic layer.   
     
     
         20 . The thermal barrier as claimed in  claim 19 , wherein the columns have a maximum width of between 10 and 300 microns. 
     
     
         21 . The thermal barrier as claimed in  claim 19 , wherein the spacings have a width of between 10 and 100 microns. 
     
     
         22 . The thermal barrier as claimed in  claim 19 , wherein the isotropic layer is made of porous ceramic. 
     
     
         23 . A turbine blade for a turbomachine comprising a thermal barrier as claimed in  claim 19 . 
     
     
         24 . A turbomachine comprising at least one turbine blade as claimed in  claim 23 .