Impeller coating

Abstract

An impeller is provided with a back surface that is at least partly coated with a thermal barrier coating. The thermal barrier coating includes an anodized layer, polymer or polymer-based ceramics.

1 . An impeller device comprising:
 an impeller with a back surface at least partly coated with a thermal barrier coating, said thermal barrier coating comprises:
 an anodized layer; and/or 
 a polymer; and/or 
 a polymer-based ceramics, said back surface being exclusively coated. 
   
   
   
       2 . The impeller device as claimed in  claim 1 , wherein the impeller is a turbocharger or centrifugal compressor impeller. 
   
   
       3 . The impeller device as claimed in  claim 1 , wherein the coating has a minimal thickness of 0.05 mm. 
   
   
       4 . The impeller device as claimed in  claim 1 , wherein the thermal conductivity of the coating is in the order of 1/10 to 1/1000 of an impeller substrate. 
   
   
       5 . The impeller device as claimed in  claim 1 , wherein the thermal barrier coating comprises multiple layers. 
   
   
       6 . The impeller device as claimed in  claim 5 , wherein the multiple layers have an outer layer with visually distinguishing characteristics. 
   
   
       7 . The impeller device as claimed in  claim 5 , wherein the multiple layers are dual layers comprising a polymer and an anodized layer. 
   
   
       8 . The impeller device as claimed in  claim 1 , wherein the polymer is a thermoplastic. 
   
   
       9 . The impeller device as claimed in  claim 8 , wherein the polymer is a reinforced thermoplastic. 
   
   
       10 . The impeller device as claimed in  claim 9 , wherein the thermoplastic is reinforced by glass fibre. 
   
   
       11 . The impeller device as claimed in  claim 9 , wherein the thermoplastic is reinforced carbon fibre. 
   
   
       12 . The impeller device as claimed in  claim 1 , wherein the polymer comprises Polyphthalamid, Polyetherketon, Polyetherkethonekethon, Polyetheretherketon, Polytetrafluorethylen or Thermoplastic Polyimid. 
   
   
       13 . The impeller device, as claimed in  claim 1 , wherein the polymer-based ceramics comprises Polyphthalamid, Polyetherketon, Polyetherkethonekethon, Polyetheretherketon, Polytetrafluorethylen or Thermoplastic Polyimid.