Process for Applying a Bonding Primer Layer

Abstract

A process for applying a bonding primer layer for a protective ceramic layer on a component surface by high-velocity flame spraying is proposed. A coating material in the foam of at least one metal alloy powder is at least partially melted and is applied as particle stream with high velocity to the component surface. The coating material has two powder fractions that have a fine particle size and a coarse particle size. The coating material comprises an agglomerated and sintered powder.

1 .- 12 . (canceled) 
     
     
         13 . A process for applying a bonding primer layer for a protective ceramic coating on a component surface by high-velocity flame spraying, comprising:
 at least partially melting a coating material comprising a fine grain size fraction and a coarse grain size fraction for producing an agglomerated and sintered powder; and   emitting the melted coating material as a particle stream onto the component surface at a high velocity for applying the bonding primer layer.   
     
     
         14 . The process as claimed in  claim 13 , wherein the fine grain size fraction is in a range of 60% by volume to 80% by volume. 
     
     
         15 . The process as claimed in  claim 14 , wherein the fine grain size fraction is in a range of 65% by volume to 75% by volume. 
     
     
         16 . The process as claimed in  claim 15 , wherein the fine grain size fraction is in a range of 65% by volume to 70% by volume. 
     
     
         17 . The process as claimed in  claim 13 , wherein the coating material is a metal alloy powder selected from the group consisting of: NiAl, MCrAlY, MCrAl, aluminum containing intermetallic materials, chromium containing intermetallic materials, and combinations thereof. 
     
     
         18 . The process as claimed in  claim 13 , further comprising:
 initially coating the component surface with a bottom layer by a metal alloy powder having a fine grain size, and   applying a top layer covering the bottom layer by the coating material comprising the fine grain size fraction and the coarse grain size fraction.   
     
     
         19 . The process as claimed in  claim 18 , wherein the bottom layer is produced by the fine grain size fraction of the coating material of the top layer. 
     
     
         20 . The process as claimed in  claim 13 , wherein the coarse powder fraction has a particle size distribution of 45 μm to 75 μm. 
     
     
         21 . The process as claimed in  claim 20 , wherein the coarse powder fraction has a particle size distribution of 22 μm to 63 μm. 
     
     
         22 . The process as claimed in  claim 13 , wherein the fine powder fraction has a particle size distribution of 11 to 44 μm. 
     
     
         23 . The process as claimed in  claim 22 , wherein the fine powder fraction has a particle size distribution of 16 μm to 44 μm 
     
     
         24 . The process as claimed in  claim 13 , wherein the fine powder has a particle size distribution of 22 μm to 53 μm. 
     
     
         25 . The process as claimed in  claim 13 , wherein at least 90% particles of the fine powder fraction are smaller than particles of the coarse powder fraction. 
     
     
         26 . The process as claimed in  claim 13 , wherein the fine powder fraction and the coarse powder fraction have an identical composition. 
     
     
         27 . The process as claimed in  claim 13 , wherein a ceramic thermal barrier coating is applied to the bonding primer layer. 
     
     
         28 . The process as claimed in  claim 27 , wherein the ceramic thermal barrier coating comprises an APS thermal barrier coating. 
     
     
         29 . The process as claimed in  claim 13 , wherein the bonding primer layer is applied to a surface of a turbine blade or vane.