Method for coating a substrate

Abstract

A method of coating a substrate is proposed, in which a starting material in the form of a process beam is sprayed onto a surface of the substrate by means of thermal spraying, wherein the surface of the substrate is initially pretreated with a plasma flame of a plasma spray device without material deposition and the process beam including the starting material is subsequently applied onto the surface.

1 . A method of coating a substrate in which a starting material in the form of a process beam is sprayed onto a surface of the substrate by means of thermal spraying, wherein the surface of the substrate is initially pretreated with a plasma flame of a plasma spray device without material deposition and the process beam including the starting material is subsequently applied onto the surface. 
     
     
         2 . The method in accordance with  claim 1 , in which the substrate is metallic. 
     
     
         3 . The method in accordance with  claim 1 , in which the starting material is a metallic material or a ceramic material. 
     
     
         4 . The method in accordance with  claim 1 , in which the thermal spraying is a plasma spraying. 
     
     
         5 . The method in accordance with  claim 1 , which is carried out at a process pressure which is smaller than the atmospheric pressure. 
     
     
         6 . The method in accordance with  claim 1 , in which a thermal spray apparatus for generating the process beam and the plasma spray device are commonly moved relative to the surface of the substrate separate from one another in time or space, such that the plasma flame initially pretreats a region of the surface and subsequently after a predeterminable time frame, the process beam is subsequently applied onto the same region. 
     
     
         7 . The method in accordance with  claim 1 , in which the surface of the substrate is pretreated by the plasma spray device without material deposition and the process beam is subsequently generated for the coating with the same plasma spray device. 
     
     
         8 . The method in accordance with  claim 7 , in which the plasma flame for pretreating is generated using substantially the same plasma parameters as the plasma flame for generating the process beam, in particular using the same current, the same gas and the same gas flow rate. 
     
     
         9 . The method in accordance with  claim 7 , in which the spacing between an exit nozzle of the plasma spray device and the surface of the substrate for the pretreatment and the application of the process beam are of equal size. 
     
     
         10 . The method in accordance with  claim 1 , in which the time span between the pretreatment and the application of the same region with the process beam amounts to at most 5 minutes. 
     
     
         11 . The method in accordance with  claim 1 , in which the time span between the pretreatment and the application of the same region with the process beam amounts to at most one minute.