Process for manufacturing a microstructured coating, and wall having such a coating

Abstract

This relates to a process for manufacturing a microstructured coating on a substrate, which comprises a step of spraying molten particles having a diameter comprised between 0.05 μm and 5 μm onto the substrate, the spraying being carried out by at least one plasma torch, which is moved relative to the substrate, the movement parameters and/or the flowrate of particles sprayed by the plasma torches being variable as a function of the position of the plasma torches, ensuring a variable thickness for the coating formed by the particles, at various points of the substrate. The embodiment also relates to a wall having a coating obtained by this process.

1 . A process for manufacturing a microstructured coating on a substrate comprising:
 spraying molten particles having a diameter between 0.05 μm and 5 μm onto said substrate, the spraying being carried out by at least one plasma torch, which is moved relative to the substrate, the movement parameters and/or the flowrate of particles sprayed by the plasma torch(es) being variable as a function of the position of the plasma torch(es), and   ensuring a variable thickness for the coating formed by the particles, at various points of the substrate.   
     
     
         2 . The process of  claim 1 , wherein the variable thickness is produced by spraying, onto at least one portion of the surface of said substrate, at least two successive layers of molten particles, the number of layers of particles sprayed being variable at various points of the substrate. 
     
     
         3 . The process of  claim 2 , wherein variable thickness is produced by spraying at least one layer of molten particles the thickness of which is variable at various points of the substrate. 
     
     
         4 . The process of  claim 3 , further comprising a robot that controls the position, the orientation and the flowrate of each of the plasma torches spraying particles onto the substrate. 
     
     
         5 . The process of  claim 4 , the spraying step comprises:
 spraying a first layer of particles, of substantially uniform thickness at every point on the substrate; and   spraying, on top of the first layer, a plurality of other layers of particles, the number and/or thickness of which are different at various points of the substrate.   
     
     
         6 . The process of  claim 5 , wherein the spraying step comprises:
 spraying layers of particles, the number and/or thickness of which are different at various points of the substrate ( 20 ,  30 ,  40 ,  80 ); and   spraying on top of the preceding layers of particles at least one external layer of particles, of substantially uniform thickness at every point of the substrate.   
     
     
         7 . The process of  claim 6 , wherein prior to the spraying step, a step of measuring the geometry of the surface of the substrate and a step of calculating the thickness and/or the number of layers of particles to be sprayed at various points of the substrate ( 20 ,  30 ,  40 ,  80 ). 
     
     
         8 . The process of  claim 7 , the particles sprayed in the spraying step comprise particles of metal oxide. 
     
     
         9 . The process of  claim 8 , wherein, prior to the spraying step, a step of dispersing particles to be sprayed in a sol-gel type compound is performed. 
     
     
         10 . The process of  claim 9 , wherein the particles sprayed in the spraying step comprise particles of zirconia. 
     
     
         11 . The process of  claim 9  wherein the particles sprayed in said spraying step comprise particles of titanium dioxide. 
     
     
         12 . A wall, comprising:
 a substrate; and   a coating covering the substrate, wherein the coating is a microstructured coating.   
     
     
         13 . The wall of  claim 12 , wherein the coating has an average thickness between 0.01 mm and 0.25 mm. 
     
     
         14 . The wall of  claim 12 , wherein the coating has, on its surface, a microstructure forming ribs that are substantially parallel to one another. 
     
     
         15 . The wall of  claim 14 , wherein the ribs have a height of between 10 μm and 60 μm.