Methods of manufacturing casted articles, and systems

Abstract

A method for manufacturing a casted article is presented. The method includes steps of forming a casted article by a liquid metal cooled directional solidification process, removing a metallic material from a surface of the casted article and inspecting the surface of the casted article. The surface of the casted article is inspected for the presence of the metallic material by exposing the surface to a visualization reagent. A system for manufacturing the casted article is also presented.

1 . A method, comprising steps of:
 forming a casted article by a liquid metal cooled directional solidification process;   removing a metallic material from a surface of the casted article; and   inspecting for the presence of the metallic material on the surface of the casted article by exposing the surface to a visualization reagent.   
   
   
       2 . The method of  claim 1 , wherein removing the metallic material from the surface of the casted article, comprises a chemical process. 
   
   
       3 . The method of  claim 1 , wherein the chemical process comprises contacting the metallic material with an aqueous composition which comprises an acid having the formula H x AF 6 , wherein A is silicon, germanium, titanium, zirconium, aluminum, or gallium, and x is 1-6. 
   
   
       4 . The method of  claim 3 , wherein x is 1-3. 
   
   
       5 . The method of  claim 3 , wherein contacting comprises immersing the casted article in a bath of the aqueous composition. 
   
   
       6 . The method of  claim 1 , wherein the casted article comprises iron, cobalt, nickel, aluminum, chromium, titanium, or a combination thereof. 
   
   
       7 . The method of  claim 1 , wherein the casted article comprises a superalloy material. 
   
   
       8 . The method of  claim 1 , wherein the casted article is an airfoil. 
   
   
       9 . The method of  claim 1 , wherein the metallic material comprises tin, iron, cobalt, nickel, aluminum, chromium, titanium or a combination thereof. 
   
   
       10 . The method of  claim 1 , wherein inspecting comprises the steps of:
 applying an extraction reagent to the surface of the casted article;   exposing the surface to the visualization reagent, and   observing a response of the visualization reagent.   
   
   
       11 . The method of  claim 10 , wherein the response of the visualization reagent results in one or more of a calorimetric response, absorbance, scatter and fluorescence. 
   
   
       12 . The method of  claim 10 , wherein the extraction reagent comprises an acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, acetic acid, and a combination thereof. 
   
   
       13 . The method of  claim 12 , wherein acid is present at a 1 to 10% weight volume. 
   
   
       14 . The method of  claim 1 , wherein the visualization reagent comprises a fluoresent dye or an optically active material. 
   
   
       15 . The method of  claim 1 , wherein the visualization reagent comprises a calorimetric reagent. 
   
   
       16 . The method of  claim 15 , wherein the colorimetic reagent comprises pyrocatechol violet. 
   
   
       17 . The method of  claim 16 , wherein pyrocatechol violet is present in the composition range of from about 10 −5  M to about 10 −3  M. 
   
   
       18 . The method of  claim 16 , wherein the color obtained by the calorimetric reagent is a dark blue color thereby indicating the presence of the metallic material on the surface. 
   
   
       19 . The method of  claim 16 , wherein the color obtained by the calorimetric reagent is a pink color thereby indicating the absence of the metallic material on the surface. 
   
   
       20 . A method, comprising:
 filling a mold with a molten metal;   immersing the mold into a cooling metallic liquid progressively, to cause a solidification interface to pass through the molten metal;   recovering a casted article from the mold;   removing a metallic material from a surface of the casted article; and   inspecting for the presence of the metallic material on the surface of the casted article by exposing the surface to a visualization reagent.   
   
   
       21 . A system, comprising:
 a heating furnace at a temperature above the liquidus temperature of a metal within a mold;   a liquid cooling bath comprising a cooling metallic liquid;   a bath comprising an aqueous composition to remove a metallic material from a surface of a casted article;   a unit to expose at least a portion of the casted article to a visualization reagent; and   a visualization aid for observing a response of the visualization reagent.   
   
   
       22 . The system of  claim 21 , wherein the unit is a cotton-tipped swab, a block paper, a sprayer, a bath, a glass pipe or a glass rod. 
   
   
       23 . The system of  claim 21 , wherein the visualization aid is an optical system or human eye. 
   
   
       24 . The system of  claim 23 , wherein the optical system is a light source, an optical detector, an optical differentiator or a combination thereof.