Thermal barrier coating systems and methods of making and using the same

Abstract

A method for coating a surface of a substrate is provided. The method includes providing a suspension or a precursor comprising feedstock material suspended in a liquid medium. Further, the method includes spraying the suspension or the precursor onto the surface at a spray angle less than about 75 degrees to a tangent of the surface.

1 . A method for coating a surface of a substrate, comprising:
 providing a suspension comprising feedstock material suspended in a liquid medium; and   spraying the suspension onto the surface at a spray angle less than about 75 degrees to a tangent of the surface.   
     
     
         2 . The method of  claim 1 , wherein the feedstock material comprises fine particles suspended in the liquid medium or a precursor material of a thermal barrier coating. 
     
     
         3 . The method of  claim 2 , wherein the fine particles have a median diameter in a range from about 0.1 micrometers to about 10 micrometers. 
     
     
         4 . The method of  claim 2 , wherein an amount of the fine particles suspended in the liquid medium is in a range from about 5 weight percent to about 40 weight percent. 
     
     
         5 . The method of  claim 2 , wherein the fine particles comprise an oxide. 
     
     
         6 . The method of  claim 2 , wherein the fine particles comprise an oxide stabilized with a stabilizing agent, stabilized zirconia, yttria-stabilized zirconia, a zirconate, a hafnate, or a cerate. 
     
     
         7 . The method of  claim 1 , wherein providing the suspension comprises:
 forming first and second intermediate suspensions, wherein the feedstock material in each intermediate suspension comprises fine particles having a median diameter that is different from that of the other intermediate suspension; and   mixing together the two intermediate suspensions to obtain the suspension.   
     
     
         8 . The method of  claim 1 , wherein providing and spraying the suspension comprises:
 feeding the suspension to a plasma spray gun; and   injecting the suspension into a plasma plume of the plasma spray gun for deposition onto the surface of the substrate.   
     
     
         9 . The method of  claim 1 , wherein the substrate comprises a component of a gas turbine assembly. 
     
     
         10 . The method of  claim 1 , wherein spraying is performed onto the surface at a spray angle of about 20 degrees to about 60 degrees. 
     
     
         11 . The method of  claim 1 , wherein spraying is performed onto the surface at a spray angle of about 45 degrees to about 75 degrees. 
     
     
         12 . The method of  claim 1 , further comprising depositing a bondcoat on the surface of the substrate using vapor phase aluminizing, or vapor phase deposition. 
     
     
         13 . The method of  claim 12 , comprising roughening a surface of the bondcoat. 
     
     
         14 . A method for providing a thermal barrier on a substrate, comprising:
 depositing a bondcoat on a surface of the substrate;   providing a suspension comprising feedstock material suspended in a liquid medium; and   plasma-spraying the suspension onto the surface at a spray angle in a range from about 20 degrees to about 75 degrees to a tangent of the surface.