Method for removing carbide-based coatings

Abstract

The present invention is a method for processing a metal component comprising exposing a carbide-based coating to fluoride ions, thereby extracting a carbide material from the carbide-based coating to provide a residual coating on the metal component, and removing the residual coating from the metal component.

1 . A method for processing a metal component having a carbide-based coating, the method comprising:
 exposing the carbide-based coating to fluoride ions, thereby extracting a carbide material from the carbide-based coating to provide a residual coating on the metal component; and   removing the residual coating from the metal component.   
   
   
       2 . The method of  claim 1 , further comprising heating the metal component to a temperature of at least about 820° C. 
   
   
       3 . The method of  claim 2 , wherein the metal component comprises a material selected from the group consisting of a nickel-based alloy, a nickel-based superalloy, a cobalt-based alloy, a cobalt-based superalloy, and combinations thereof. 
   
   
       4 . The method of  claim 1 , wherein at least about 50% by weight of the carbide material is extracted from the chromium carbide-based coating, based on a pre-extraction weight of the carbide-based coating. 
   
   
       5 . The method of  claim 4 , wherein at least about 75% by weight of the carbide material is extracted from the carbide-based coating. 
   
   
       6 . The method of  claim 5 , wherein at least about 90% by weight of the carbide material is extracted from the carbide-based coating. 
   
   
       7 . The method of  claim 1 , wherein the residual coating is removed from the metal component with a first removal pressure that is less than 25% of a second removal pressure required to remove the carbide-based coating from the metal component in a same duration. 
   
   
       8 . The method of  claim 7 , wherein the first removal pressure is less than 10% of the second removal pressure. 
   
   
       9 . The method of  claim 8 , wherein the first removal pressure is less than 5% of the second removal pressure. 
   
   
       10 . The method of  claim 1 , wherein the carbide material is selected from the group consisting of chromium carbide materials, tungsten carbide materials, and combinations thereof. 
   
   
       11 . A method for processing a metal component, the method comprising:
 exposing the metal component to hydrogen fluoride, the metal component having a surface and a carbide-based coating disposed on at least a portion of the surface;   heating the metal component to react the hydrogen fluoride with the carbide-based coating, thereby providing a residual coating on the surface of the metal component; and   removing the residual coating from the surface of the metal component.   
   
   
       12 . The method of  claim 10 , wherein the metal component is heated to a temperature of at least about 820° C. 
   
   
       13 . The method of  claim 1 , wherein the hydrogen fluoride reacts with the carbide-based coating until at least about 50% by weight of a carbide material is extracted from the carbide-based coating, based on a pre-extraction weight of the carbide-based coating. 
   
   
       14 . The method of  claim 13 , wherein at least about 75% by weight of the carbide material is extracted from the carbide-based coating. 
   
   
       15 . The method of  claim 14 , wherein at least about 90% by weight of the carbide material is extracted from the carbide-based coating. 
   
   
       16 . A method for processing a metal component having a first coating, the method comprising:
 extracting a carbide material from the first coating with hydrogen fluoride to provide a second coating having a first removal pressure from the metal component that is less than 25% of a second removal pressure required to remove the first coating from the metal component in a same duration; and   removing the residual coating from the metal component.   
   
   
       17 . The method of  claim 16 , wherein extracting the carbide material from the first coating with hydrogen fluoride comprises generating fluoride ions from the hydrogen fluoride. 
   
   
       18 . The method of  claim 16 , wherein the carbide material comprises at least one of: a chromium carbide material and a tungsten carbide material. 
   
   
       19 . The method of  claim 16 , wherein the first removal pressure is less than 10% of the second removal pressure. 
   
   
       20 . The method of  claim 19 , wherein the first removal pressure is less than 5% of the second removal pressure.