Process for producing a compressor

Abstract

A compressor housing of a turbocharger is provided with an abrasion coating on the inner wall which cooperates with the compressor wheel. The production of the abrasion coating by means of plasma spraying does not require any activation in-depth of the surface and may be applied directly onto the surface of the compressor housing wall which is, for example rough turned. The coating has a constant porosity and a relative small particle size.

1 . Process of producing a compressor housing of an exhaust gas turbocharger comprising a rotationally symmetrical wall, the inner side of which is provided with an abrasion coating, comprising: 
 manufacturing a compressor housing by means of a manufacturing procedure which includes rough turning, and    coating the inner side of the wall of the compressor housing with an abrasion coating without an intermediate activation step of the wall that is independent from the production process.    
   
   
       2 . The process according to  claim 1 , further comprising the step of providing a finishing treatment of the coated surface.  
   
   
       3 . Process according to  claim 1 , wherein the production of the abrasion coating is effected by means of atmospheric plasma spraying.  
   
   
       4 . Process according to  claim 1 , wherein the production of the abrasion coating is effected by means of plasma spraying a mixture of aluminium-silicon and polyester.  
   
   
       5 . Process according to  claim 4 , wherein Sulzer Metco NS 601 is used as a mixture of aluminium-silicon and polyester.  
   
   
       6 . Process according to  claim 1 , wherein the coating parameters are chosen in such a manner that the average particle size of the abrasion coating amounts to about 4 microns.  
   
   
       7 . Process according to  claim 1 , wherein the coating parameters are chosen in such a manner that the porosity of the abrasion coating is constant throughout the coating's thickness.  
   
   
       8 . Compressor housing comprising a rotationally symmetrical inner wall for receiving a compressor wheel which rotates about a central axis within the compressor housing, wherein the edge regions thereof, being remote from the central axis in radial direction, move at a relative small distance to the contour of the rotationally symmetrical inner wall along this contour, the inner wall of the compressor housing having an abrasion coating which is swept by the edge regions of the compressor wheel, thereby adapting the surface of the abrasion coating, during an early operational phase of the compressor, to the edge contour of the compressor wheel, and wherein the abrasion coating is produced by a powder mixture of aluminium-silicon and polyester, without an intermediate activation step of the inner wall that is independent of the production process.  
   
   
       9 . Compressor housing according to  claim 8 , wherein the abrasion coating comprises a fine grain structure having an average particle size of about 4 microns, as may be, for example, be produced by atmospheric plasma spraying.  
   
   
       10 . Compressor housing according to  claim 8 , wherein a region of the inner contour of the compressor housing, which together with the compressor wheel forms a rotationally symmetrical gap, is provided with an abrasion coating.  
   
   
       11 . Compressor housing according to  claim 8 , wherein, apart from an area of the inner wall of the compressor housing that cooperates with the compressor wheel, an intake area of the compressor housing is also provided with an abrasion coating.  
   
   
       12 . Compressor housing according to  claim 8 , wherein a powder mixture of AISi12 plus polyester (SulzerMetco NS 601) is used as a basic material for producing the abrasion coating.  
   
   
       13 . Compressor housing according to  claim 8 , wherein the porosity of the coating is constant throughout the coating's thickness.  
   
   
       14 . The use of a compressor housing according to  claim 8  as a housing of a turbocharger compressor.