Localized cleaning process and apparatus therefor

Abstract

Methods and apparatuses by which an oxidized metallic surface can be prepared for a subsequent repair operation without excessive removal of parent metal material. At least one gas is supplied to a limited portion of a metallic surface of a component, and the limited portion is locally heated in the presence of the gas to a treatment temperature sufficient to cause the gas or a gas that forms therefrom to chemically remove oxides from the limited portion of the metallic surface. At least a second portion of the metallic surface is not locally heated to the treatment temperature.

1 . An apparatus comprising:
 means for supplying at least one gas to a limited portion of a metallic surface of a component; and   means for locally heating the limited portion of the metallic surface in the presence of the at least one gas to a treatment temperature sufficient to cause the at least one gas or a gas that forms therefrom to chemically remove oxides from the limited portion of the metallic surface and not from at least a second portion of the metallic surface that is not locally heated to the treatment temperature.   
     
     
         2 . The apparatus according to  claim 1 , wherein the at least one gas is a fluoride-containing gas, the apparatus further comprises means for supplying hydrogen to the limited portion of the component, and the heating means is operable to react the hydrogen and the fluoride-containing gas to form hydrogen fluoride at the limited portion of the component and not at the second portion of the component. 
     
     
         3 . The apparatus according to  claim 2 , wherein the fluoride-containing gas is a fluorocarbon. 
     
     
         4 . The apparatus according to  claim 1 , wherein the heating means limits the treatment temperature to not more than 1150° C. 
     
     
         5 . The apparatus according to  claim 1 , wherein the locally heating step is performed with an induction coil configured to surround the limited portion of the component and not the second portion of the component. 
     
     
         6 . The apparatus according to  claim 1 , the apparatus further comprising a chamber containing the heating means and into which the supplying means supplies the at least one gas. 
     
     
         7 . The apparatus according to  claim 6 , wherein the supplying means directly supplies the at least one gas to an interior cavity within the component, the apparatus further comprises means for supplying a second gas to an interior of the chamber, and the heating means is operable to react the at least one gas and the second gas at the limited portion of the component and not the second portion of the component.