Metallic substrate with ceramic coating and method for obtaining it

Abstract

Metallic substrate with a ceramic coating obtained by plasma electrolytic oxidation, resistant to degradation by tribocorrosion of light metals and their alloys, in a liquid and/or semi-solid state with a thickness from 10 to 300 μm and resistant to immersion in said light metals and their alloys without compositional modification of the substrate. Method for obtaining a metallic substrate with a ceramic coating by plasma electrolytic oxidation in which said substrate comprises a core and an outer layer of a metal different from that of the core or of an intermetallic compound, said outer layer being obtained by thermal spraying, laser, solid or liquid diffusion, hot galvanising or cementing. This allows obtaining a ceramic coating applicable to any metallic substrate and resistant to degradation by tribocorrosion.

1 . Metallic substrate with a ceramic coating obtained by plasma electrolytic oxidation, resistant to degradation by tribocorrosion of light metals and their alloys, in a liquid and/or semi-solid state, characterised in that said coating ( 1 ) has a thickness from 10 to 300 μm and is resistant to immersion in said light metals and their alloys without compositional modification of the substrate ( 2 ). 
     
     
         2 . Metallic substrate with a ceramic coating according to  claim 1 , wherein the metallic substrate ( 2 ) is a single metal. 
     
     
         3 . Metallic substrate with a ceramic coating according to  claim 1 , wherein the metal is titanium or zirconium. 
     
     
         4 . Metallic substrate with a ceramic coating according to  claim 1 , wherein the metallic substrate ( 2 ) comprises a metallic core and an outer layer of a metal different from that of the core, said layer being obtained by thermal spraying, hot galvanising or cementing. 
     
     
         5 . Metallic substrate with a ceramic coating according to  claim 1 , wherein the metallic substrate ( 2 ) comprises a metallic core and an outer layer of an intermetallic compound, said layer being obtained by spraying or by solid or liquid diffusion. 
     
     
         6 . Metallic substrate with a ceramic coating according to  claim 4 , wherein the core is of steel, nickel, titanium, zirconium, refractory materials or any of the alloys thereof. 
     
     
         7 . Metallic substrate with a ceramic coating according to  claim 5 , wherein the core is of steel, nickel, titanium, zirconium, refractory materials or any of the alloys thereof. 
     
     
         8 . Metallic substrate with a ceramic coating according to  claim 4 , wherein the outer layer is of a light metal selected from among aluminium, magnesium, titanium and zirconium. 
     
     
         9 . Metallic substrate with a ceramic coating according to  claim 5 , wherein the outer layer is of an intermetallic compound of titanium and aluminium. 
     
     
         10 . Metallic substrate with a ceramic coating according to  claim 1 , wherein the coating ( 1 ) has a hardness from 100 to 2000 HV. 
     
     
         11 . Metallic substrate with a ceramic coating according to  claim 2 , wherein the coating ( 1 ) has a hardness from 100 to 2000 HV. 
     
     
         12 . Metallic substrate with a ceramic coating according to  claim 3 , wherein the coating ( 1 ) has a hardness from 100 to 2000 HV. 
     
     
         13 . Metallic substrate with a ceramic coating according to  claim 4 , wherein the coating ( 1 ) has a hardness from 100 to 2000 HV. 
     
     
         14 . Metallic substrate with a ceramic coating according to  claim 5 , wherein the coating ( 1 ) has a hardness from 100 to 2000 HV. 
     
     
         15 . Metallic substrate with a ceramic coating according to  claim 6 , wherein the coating ( 1 ) has a hardness from 100 to 2000 HV. 
     
     
         16 . Metallic substrate with a ceramic coating according to  claim 7 , wherein the coating ( 1 ) has a hardness from 100 to 2000 HV. 
     
     
         17 . Metallic substrate with a ceramic coating according to  claim 8 , wherein the coating ( 1 ) has a hardness from 100 to 2000 HV. 
     
     
         18 . Metallic substrate with a ceramic coating according to  claim 9 , wherein the coating ( 1 ) has a hardness from 100 to 2000 HV. 
     
     
         19 . Metallic substrate with a ceramic coating according to  claim 1 , wherein the coating ( 1 ) has an adherence from 2 to 30 MPa. 
     
     
         20 . Metallic substrate with a ceramic coating according to  claim 2 , wherein the coating ( 1 ) has an adherence from 2 to 30 MPa. 
     
     
         21 . Metallic substrate with a ceramic coating according to  claim 3 , wherein the coating ( 1 ) has an adherence from 2 to 30 MPa. 
     
     
         22 . Metallic substrate with a ceramic coating according to  claim 4 , wherein the coating ( 1 ) has an adherence from 2 to 30 MPa. 
     
     
         23 . Metallic substrate with a ceramic coating according to  claim 5 , wherein the coating ( 1 ) has an adherence from 2 to 30 MPa. 
     
     
         24 . Metallic substrate with a ceramic coating according to  claim 6 , wherein the coating ( 1 ) has an adherence from 2 to 30 MPa. 
     
     
         25 . Metallic substrate with a ceramic coating according to  claim 7 , wherein the coating ( 1 ) has an adherence from 2 to 30 MPa. 
     
     
         26 . Metallic substrate with a ceramic coating according to  claim 8 , wherein the coating ( 1 ) has an adherence from 2 to 30 MPa. 
     
     
         27 . Metallic substrate with a ceramic coating according to  claim 9 , wherein the coating ( 1 ) has an adherence from 2 to 30 MPa. 
     
     
         28 . Metallic substrate with a ceramic coating according to  claim 1 , wherein the coating ( 1 ) has a mean roughness, R a , from 1 to 5 μm. 
     
     
         29 . Metallic substrate with a ceramic coating according to  claim 2 , wherein the coating ( 1 ) has a mean roughness, R a , from 1 to 5 μm. 
     
     
         30 . Metallic substrate with a ceramic coating according to  claim 3 , wherein the coating ( 1 ) has a mean roughness, R a , from 1 to 5 μm. 
     
     
         31 . Metallic substrate with a ceramic coating according to  claim 4 , wherein the coating ( 1 ) has a mean roughness, R a , from 1 to 5 μm. 
     
     
         32 . Metallic substrate with a ceramic coating according to  claim 5 , wherein the coating ( 1 ) has a mean roughness, R a , from 1 to 5 μm. 
     
     
         33 . Metallic substrate with a ceramic coating according to  claim 6 , wherein the coating ( 1 ) has a mean roughness, R a , from 1 to 5 μm. 
     
     
         34 . Metallic substrate with a ceramic coating according to  claim 7 , wherein the coating ( 1 ) has a mean roughness, R a , from 1 to 5 μm. 
     
     
         35 . Metallic substrate with a ceramic coating according to  claim 8 , wherein the coating ( 1 ) has a mean roughness, R a , from 1 to 5 μm. 
     
     
         36 . Metallic substrate with a ceramic coating according to  claim 9 , wherein the coating ( 1 ) has a mean roughness, R a , from 1 to 5 μm. 
     
     
         37 . Method for obtaining a metallic substrate ( 2 ) with a ceramic coating ( 1 ) by plasma electrolytic oxidation characterised in that said substrate ( 2 ) comprises a core and an outer layer of a metal different from that of the core or of an intermetallic compound, said outer layer being obtained by thermal spraying, laser, solid or liquid diffusion, hot galvanising or cementing. 
     
     
         38 . Method according to  claim 12 , wherein the thermal spraying, laser, hot galvanising and cementing is performed on a core when the coating ( 1 ) is obtained as an outer layer of a metal different from that of the core. 
     
     
         39 . Method according to  claim 12 , wherein the spraying and solid or liquid diffusion is performed on a core when the coating ( 1 ) is obtained as an outer layer of an intermetallic compound.