Method for coating the surface of a metallic material, device for carrying out said method

Abstract

The invention relates to a method for coating the surface of a metallic material having a crystallographic structure. The inventive method consists in producing a first coating of said material with a metal layer or a metal alloy layer having a melting point of T f and a thickness equal to or less than 2.5 μm, heating the first coating by a flash heating in such a way that it is heated to a temperature ranging from 0.8 T f to T f , producing a second metal or metal alloy coating with a thickness equal to or less than 1 μm. The device for carrying out said method and the thus coated metallic material are also disclosed.

1 . Method for coating the surface of a metal material having a crystallographic structure, according to which the material is first coated with a layer of a metal or a metal alloy having a melting point equal to T f  and a thickness less than or equal to 2.5 μm, characterised in that: 
 the first coating is subjected to thermal processing using a rapid heating means in order to bring the surface of the first coating to a temperature of between 0.8 T f  and T f ;    a second coating is deposited from a metal or a metal alloy having a thickness less than or equal to 1 μm.    
   
   
       2 . Method according to  claim 1 , characterised in that the first and second coatings have melting points less than or equal to 700° C.  
   
   
       3 . Method according to  claim 1 , characterised in that the first and second coatings are constituted by the same material.  
   
   
       4 . Method according to  claim 1 , characterised in that a transparent mineral film is then deposited on the second coating.  
   
   
       5 . Method according to  claim 1 , characterised in that the metal material to be coated is a carbon steel.  
   
   
       6 . Method according to  claim 1 , characterised in that the metal material to be coated is a stainless steel.  
   
   
       7 . Method according to  claim 1 , characterised in that the metal material to be coated is aluminium or one of the alloys thereof.  
   
   
       8 . Method according to  claim 1 , characterised in that the first coating is produced by means of electrodeposition.  
   
   
       9 . Method according to  claim 1 , characterised in that the first coating is produced by a physical vapour deposition method.  
   
   
       10 . Method according to  claim 1 , characterised in that the means for rapid heating is an infra-red heating device.  
   
   
       11 . Method according to  claim 1 , characterised in that the means for rapid heating is an induction heating device.  
   
   
       12 . Method according to  claim 1 , characterised in that the means for rapid heating is a device for discharge with plasma with a non-reactive gas.  
   
   
       13 . Method according to  claim 1 , characterised in that the means for rapid heating is a device for ion bombardment with a non-reactive gas.  
   
   
       14 . Method according to  claim 1 , characterised in that the second coating is produced by means of electrodeposition.  
   
   
       15 . Method according to  claim 1 , characterised in that the second coating is produced by means of a physical vapour deposition method.  
   
   
       16 . Method according to  claim 4 , characterised in that the transparent mineral film is deposited by means of a reactive plasma assisted chemical vapour deposition method.  
   
   
       17 . Method according to  claim 1 , characterised in that the first and/or second coating(s) is/are constituted by tin.  
   
   
       18 . Method according to  claim 1 , characterised in that the first and/or second coating(s) is/are constituted by aluminium.  
   
   
       19 . Method according to  claim 1 , characterised in that the mineral film is constituted by a metal oxide or a mixture of metal oxides.  
   
   
       20 . Method according to  claim 19 , characterised in that the metal oxide(s) is/are selected from the oxides of austenitic stainless steel, chromium, titanium, silicon, zinc, tin.  
   
   
       21 . Method according to  claim 1 , characterised in that the metal material is in the form of a moving strip, and in that the various method steps are carried out continuously by means of installations which are arranged successively over the path of the moving strip.  
   
   
       22 . Device for coating a metal material in the form of a strip, characterised in that it comprises means for moving the strip and, arranged successively over the path of the strip: 
 first means for coating the strip with a layer of a metal or a metal alloy having a melting point equal to T f ;    means for rapidly heating the strip which can bring the surface of the layer to a temperature of between 0.8 T f  and T f ; and    second means for coating the strip with a layer of metal or metal alloy.    
   
   
       23 . Device according to  claim 22 , characterised in that it comprises, downstream of the second means for coating the strip with a layer of a metal or a metal alloy, means for coating the strip with a transparent mineral film.  
   
   
       24 . Metal material, characterised in that it comprises, on at least one of the surfaces thereof, a metal coating having a three-dimensional visual effect, the coating being formed directly on the surface of the material.  
   
   
       25 . Metal material according to  claim 24 , characterised in that it is produced using a method according to which 
 the material is first coated with a layer of a metal or a metal alloy having a melting point equal to T f  and a thickness less than or equal to 2.5 μm,    the first coating is subjected to thermal processing using a rapid heating means in order to bring the surface of the first coating to a temperature of between 0.8 T f  and T f  and    a second coating is deposited from a metal or a metal alloy having a thickness less than or equal to 1 μm.