Component with an internal surface to be pretreated and/or coated as well as process for pretreatment and/or coating

Abstract

Prior to the thermal coating of a component generally a pretreatment of the surface to be coated is necessary, for example, a roughening by means of sand or water blasting. The problem with this type of pretreatment or coating is over-spraying, which also modifies the surfaces, which are not intended to be coated. As remedy for this, masks have been proposed which are placed in front of the internal surface prior to the pretreatment. The task of the present invention is comprised of providing an alternative to the conventional mask and partial coating processes. The task is solved in that the mask is not produced independent from the component, but rather together therewith. This occurs in the manner, that the component is produced with a local over dimensioning, which at least partially masks the areas to be not pretreated and/or not to be coated, however, allows access to the internal surface to be pretreated and/or thermally coated.

1 . A process for pretreatment and/or thermal coating of an internal surface of a component, in particular, a cylinder crank housing, comprising 
 producing on the component ( 1 ), which has the surface to be pretreated and/or to be coated, with a local over-sizing ( 2 ) such that this over-sizing at least partially masks the area not to be pretreated and/or coated, however leaves access to the internal surface to be pretreated and/or thermally coated; and    pre-treating the surface to be coated and/or the thermal coated.    
     
     
         2 . A process according to  claim 1 , wherein said component is a cylinder crank housing.  
     
     
         3 . A process according to  claim 1 , further comprising positioning a supplemental mask ( 3   a ,  3   b ) upon the over-sizing ( 2 ).  
     
     
         4 . A process according to  claim 1 , wherein at least one supplemental opening is provided.  
     
     
         5 . A process according to  claim 4 , wherein said supplemental opening is a vacuum and/or cooling opening.  
     
     
         6 . A component with an internal surface to be pretreated and/or to be coated, wherein the component ( 1 ) includes a local over-sizing ( 2 ), such that this over-sizing ( 2 ) at least partially masks the surfaces not to be pretreated and/or not to be coated, however, leaves an access to the internal surface to be pretreated and/or thermally coated.  
     
     
         7 . A component according to  claim 6 , wherein said component is a piston crank housing with a cylinder running surface.  
     
     
         8 . A component according to  claim 6 , wherein the over-sizing ( 2 ) is continuous.  
     
     
         9 . A component according to  claim 6 , wherein the over-sizing ( 2 ) does not completely mask the internal surface to be pretreated and/or to be coated, and wherein a supplemental mask ( 3   a ,  3   b ) is provided over the over-sizing ( 2 ).