Industrial Vapour Generator For Depositing An Alloy Coating On A Metal Strip

Abstract

The present invention relates to a vacuum deposition facility for depositing a metal alloy coating on a substrate ( 7 ), said facility being equipped with a vapour generator/mixer comprising a vacuum chamber ( 6 ) in the form of an enclosure provided with means for creating a vacuum state therein relative to the external environment and provided with means for the entry and exit of the substrate ( 7 ), while still being essentially sealed from the external environment, said enclosure including a vapour deposition head, called the injector ( 3 ), configured so as to create a jet of metal alloy vapour of sonic velocity towards the surface of the substrate ( 7 ) and perpendicular thereto, said ejector ( 3 ) being in sealed communication with a separate mixer device ( 14 ), which is itself connected upstream to at least two crucibles ( 11, 12 ) respectively, these containing different metals M 1 and M 2 in liquid form, each crucible ( 11, 12 ) being connected to the mixer ( 14 ) by its own pipe ( 4, 4 ′).

1 - 19 . (canceled) 
     
     
         20 . A facility for depositing under vacuum a metal alloy coating on a substrate ( 7 ), equipped with a vapor generator-mixer comprising a vacuum chamber ( 6 ) in the form of an enclosure, provided with means for ensuring a vacuum state therein relative to the external environment and provided with means for the inlet and outlet of the substrate ( 7 ), while still being essentially sealed relative to the external environment, said enclosure including a vapor deposition head, called ejector ( 3 ), configured so as to create a jet of metal alloy vapor at sonic velocity towards the surface of the substrate ( 7 ) and perpendicular thereto, said ejector ( 3 ) being in sealed communication with a separate mixer device ( 14 ), which is itself connected upstream to at least two crucibles ( 11 , 12 ), respectively, and comprising different metals M 1  and M 2  in liquid form, each crucible ( 11 , 12 ) being connected to the mixer ( 14 ) by its own pipe ( 4 , 4 ′), wherein the mixer ( 14 ) comprises a series of partitions allowing to separate at least two entering vapors, these partitions creating orifices allowing the two vapors to exit so as to be mixed in the form of alternating layers of both vapors in the direction of the exiting flow. 
     
     
         21 . The facility according to  claim 20 , wherein the mixer ( 14 ) comprises a cylindrical envelope ( 14 C) inside which, along the axis of the envelope, are located a plurality of tubes ( 14 A) arranged regularly and connected at the inlet to the supply pipe ( 4 ) of a first metal vapor, the supply pipe ( 4 ′) of a second metal vapor being connected, laterally relative to the cylindrical envelope, to the interstitial space ( 14 B) between the tubes ( 14 A), the tubes ( 14 A) and the interstitial space ( 14 B) having outlet orifices all emerging on a space ( 15 ) where the mixing of the vapors can occur. 
     
     
         22 . The facility according to  claim 20 , wherein each of said pipes ( 4 , 4 ′) comprises a proportional valve ( 5 , 5 ′), optionally with a head loss device ( 5 A). 
     
     
         23 . The facility according to  claim 22 , wherein the proportional valve ( 5 , 5 ′) is of the butterfly valve type. 
     
     
         24 . The facility according to  claim 20 , wherein the ejector ( 3 ) comprises a longitudinal exit slot for the vapor, acting as a sonic throat, extending over the entire width of the substrate and a filtering medium or a head loss member ( 3 A) made of sintered material, preferably made of titanium or in the form of a metal sieve with sintered stainless steel fibers, so as to equalize and rectify the velocity vectors of the vapor leaving the ejector ( 3 ). 
     
     
         25 . The facility according to  claim 24 , including means for adjusting the length of the slot to the width of the substrate. 
     
     
         26 . The facility according to  claim 25 , wherein said means comprise a means for rotating the ejector ( 3 ) around its supply pipe ( 4 ). 
     
     
         27 . The facility according to  claim 20 , wherein the ejector ( 3 ), the mixer ( 14 ), the pipes ( 4 , 4 ′), and the crucibles ( 11 , 12 ) are thermally isolated from the outside environment and heated by a radiation heater. 
     
     
         28 . The facility according to  claim 20 , including optional heating means for the vacuum enclosure ( 6 ). 
     
     
         29 . The facility according to  claim 21 , wherein a first porous surface is arranged at the outlet of the tubes ( 14 A) and/or a second porous surface is arranged at the outlet of the interstitial space ( 14 B), so as to balance the pressures of the two respective vapors. 
     
     
         30 . The facility according to  claim 20 , wherein the substrate ( 7 ) is a continuously moving metal strip. 
     
     
         31 . The facility according to  claim 20 , allowing to directly deposit on the substrate ( 7 ), by a vapor jet at sonic velocity, an alloy of the first metal M 1  and of the second metal M 2 , wherein an additional pipe ( 4 ″) is mounted in bypass on the supply pipe ( 4 ′) of the first metal M 1  towards the mixer ( 14 ), having an isolating valve ( 5 ′) and leading to an additional ejector ( 3 ′) in the vacuum chamber ( 6 ), said additional ejector ( 3 ′) being configured to create a vapor jet of the first metal M 1  at sonic velocity towards and perpendicular to the surface of the substrate ( 7 ), the portion of the supply pipe ( 4 ′) of the first metal M 1  leading to the mixer ( 14 ) being provided with an additional valve ( 5 B) intended to isolate the first crucible ( 12 ) from the mixer ( 14 ). 
     
     
         32 . A method for depositing a metal alloy coating on a substrate ( 7 ), preferably a metal strip in continuous motion, using the facility according to  claim 20 , wherein:
 the flow velocity of each of the metal vapors is regulated at the inlet of the mixer ( 14 ) so that said flow velocity of said vapors at the inlet of the mixer is lower by a factor of 10, preferably by a factor of 50, than sonic velocity;   the concentration of each metal is independently adjusted during the mixture of the vapors to be deposited on the substrate ( 7 ).   
     
     
         33 . The method according to  claim 32 , wherein the flow velocity is less than 100 m/s, preferably from 5 to 50 m/s. 
     
     
         34 . The method according to  claim 32 , for implementing the facility for depositing under vacuum a metal alloy coating on a substrate ( 7 ), preferably a metal strip in continuous motion, wherein, said additional valve ( 5 B) being closed and said isolating valve ( 5 ′) being open, the first metal M 1  is successively deposited at the level of the additional ejector ( 3 ′) and the second metal M 2  is deposited at level of the ejector ( 3 ) in the vacuum chamber ( 6 ) on the substrate ( 7 ). 
     
     
         35 . The method according to  claim 32 , for implementing the facility for depositing under vacuum a metal alloy coating on a substrate ( 7 ), preferably a metal strip in continuous motion, wherein, said additional valve ( 5 B) being open and said isolating valve ( 5 ′) being closed, the M 1 +M 2  alloy is directly deposited on the substrate ( 7 ) at the level of the ejector ( 3 ) in the vacuum chamber ( 6 ). 
     
     
         36 . The method according to  claim 32 , for implementing the facility for depositing under vacuum a metal alloy coating on a substrate ( 7 ), preferably a metal strip in continuous motion, wherein, both the additional valve ( 5 B) and the isolating valve ( 5 ′) being open, the first metal M 1  is successively deposited on the substrate ( 7 ) at the level of the additional ejector ( 3 ′) and the M 1 +M 2  alloy is directly deposited at the level of the ejector ( 3 ) in the vacuum chamber ( 6 ). 
     
     
         37 . The method according to  claim 32 , wherein the metal or alloy deposition(s) are followed by a thermal treatment.