Method for coating by thermal spraying with an inclined particle jet

Abstract

A substrate is coated by cold-gas spraying in which a particle jet is oriented at an inclination to the surface of a substrate thus forming a spraying angle. To increase the possible spraying angle compared to the known art, the surface is applied with a directional patterning, for example trenches and ridges. The orientation of this patterning has an angle of inclination in the direction of the spraying angle. As a result, the adhesion of striking particles is improved and it is possible to achieve larger spraying angles.

1 - 12 . (canceled) 
     
     
         13 . A method for coating a substrate by thermal spraying, comprising:
 producing a structured surface of the substrate by pretreating the substrate, the structured surface having structure elements that are obliquely produced; and   depositing particles of a particle jet onto the substrate by directing the particle jet onto the structured surface of the substrate at a spray angle between an axis of the particle jet and a surface normal of the substrate when the substrate is untreated, the structure elements being oriented towards the axis of the particle jet during the thermal spraying and having a spatial extent that is smaller, at least in a spray angle plane in which the spray angle lies, than an average diameter of the particles.   
     
     
         14 . The method as claimed in  claim 13 , wherein the structure elements have an inclination angle substantially corresponding to the spray angle. 
     
     
         15 . The method as claimed in  claim 14 , wherein the spray angle plane and an inclination plane in which the inclination angle of the structure elements form an angle of at most 25°. 
     
     
         16 . The method as claimed in  claim 16 , wherein the structure elements include trenches with symmetry planes oriented obliquely during production such that the symmetry planes are oriented towards the axis of the particle jet during the thermal spraying. 
     
     
         17 . The method as claimed in  claim 15 , wherein the structure elements are holes with symmetry axes oriented towards the axis of the particle jet during the thermal spraying. 
     
     
         18 . The method as claimed in  claim 15 , wherein the thermal spraying is cold gas spraying. 
     
     
         19 . The method as claimed in  claim 18 , wherein the substrate, prior to said pretreating, has a region inaccessible to the particle jet while observing a maximum permissible spray angle, and
 wherein said pretreating produces the structure elements in the region that enable the particle jet at the maximum permissible spray angle to coat the region with the particles.   
     
     
         20 . The method as claimed in  claim 19 , wherein said pretreating produces the structure elements using at least one of a laser beam, an erosion method, chip removal, a shaping method, and application of a chemical. 
     
     
         21 . The method as claimed in  claim 20 , further comprising repeating said pretreating and said depositing, thereby producing layers of the particles until a desired coating is produced. 
     
     
         22 . The method as claimed in  claim 21 , wherein the substrate with the desired coating is a blade drilling of a gas turbine. 
     
     
         23 . The method as claimed in  claim 13 , wherein the spray angle plane and an inclination plane in which the inclination angle of the structure elements form an angle of at most 25°. 
     
     
         24 . The method as claimed in  claim 13 , wherein the structure elements include trenches. 
     
     
         25 . The method as claimed in  claim 24 , wherein the trenches have symmetry planes oriented obliquely during production such that the symmetry planes are oriented towards the axis of the particle jet during the thermal spraying. 
     
     
         26 . The method as claimed in  claim 13 , wherein the structure elements are holes. 
     
     
         27 . The method as claimed in  claim 26 , wherein the holes have symmetry axes oriented towards the axis of the particle jet during the thermal spraying. 
     
     
         28 . The method as claimed in  claim 13 , wherein the thermal spraying is cold gas spraying. 
     
     
         29 . The method as claimed in  claim 13 , wherein the substrate, prior to said pretreating, has a region inaccessible to the particle jet while observing a maximum permissible spray angle, and
 wherein said pretreating produces the structure elements in the region that enable the particle jet at the maximum permissible spray angle to coat the region with the particles.   
     
     
         30 . The method as claimed in  claim 13 , wherein said pretreating produces the structure elements using at least one of a laser beam, an erosion method, chip removal, a shaping method, and application of a chemical. 
     
     
         31 . The method as claimed in  claim 13 , further comprising repeating said pretreating and said depositing, thereby producing layers of the particles until a desired coating is produced. 
     
     
         32 . The method as claimed in  claim 13 , wherein the substrate after the coating is a blade drilling of a gas turbine.