Method for applying a high-temperature stable coating layer on the surface of a component and component with such a coating layer

Abstract

The invention proposes a method for applying a high-temperature stable coating layer on the surface of a component, which includes: providing a component with a surface to be coated; providing a powder material containing at least a fraction of sub-micron powder particles; and applying said powder material to the surface of the component by means of a spraying technique to build up a coating layer, whereby said sub-micron powder particles are each at least partially surrounded by an oxide shell and establish with their oxide shells an at least partially interconnected sub-micron oxide network within said coating layer.

1 . A method for applying a high-temperature stable coating layer on the surface of a component, the method comprising:
 providing a component with a surface to be coated;   providing a powder material containing at least a fraction of sub-micron powder particles; and   applying said powder material to the surface of the component by means of a spraying technique to build up a coating layer, whereby   said sub-micron powder particles are each at least partially surrounded by an oxide shell and establish with their oxide shells an at least partially interconnected sub-micron oxide network within said coating layer.   
     
     
         2 . The method according to  claim 1 , wherein said powder material is applied to the surface of the component by means of a thermal spraying technique. 
     
     
         3 . The method according to  claim 2 , wherein the thermal spraying technique used is one of High Velocity Oxygen Fuel Spraying (HVOF), Low Pressure Plasma Spraying (LPPS), Air Plasma Spraying (APS) or Suspension Plasma Spraying (SPS). 
     
     
         4 . The method according to  claim 1 , wherein said powder material has the form of agglomerates. 
     
     
         5 . The method according to  claim 1 , wherein said powder material has the form of a suspension. 
     
     
         6 . The method according to  claim 1 , wherein the powder material contains powder particles of micron size and/or larger agglomerates, and that the sub-micron particles powder particles are in said coating layer distributed around the surface of said powder particles of micron size and/or said larger agglomerates. 
     
     
         7 . The method according to  claim 1 , wherein the sub-micron powder particles are pre-oxidized before being incorporated into said coating layer. 
     
     
         8 . The method according to  claim 7 , wherein the pre-oxidation takes place in-flight during spraying. 
     
     
         9 . The method according to  claim 7 , wherein the pre-oxidation is done by an oxidative pre heat treatment of the powder material. 
     
     
         10 . The method according to  claim 1 , wherein the powder material is a metallic powder. 
     
     
         11 . The method according to  claim 10 , wherein the powder material is of the MCrAlY type with M=Fe, Ni, Co or combinations thereof. 
     
     
         12 . The method according to  claim 1 , wherein the coating layer is a bond coat or an overlay coating. 
     
     
         13 . A component for use in a high-temperature environment, said component comprising a surface, which is coated with a coating layer, wherein said coating layer comprises sub-micron powder particles, which are each at least partially surrounded by an oxide shell and establish with their oxide shells an at least partially interconnected sub-micron oxide network within said coating layer. 
     
     
         14 . The component according to  claim 13 , wherein said coating layer further comprises powder particles of micron size and/or larger agglomerates. 
     
     
         15 . The component according to  claim 14 , wherein said sub-micron powder particles are in said coating layer distributed around the surface of said powder particles of micron size and/or said larger agglomerates. 
     
     
         16 . The component according to  claim 13 , wherein the coating layer is a bond coat and the powder material is of the MCrAlY type with M=Ni, Co, Fe or combinations thereof.