Corrosion resistance for a leaching process

Abstract

A corrosion resistance system is disclosed that can be used in conjunction with a leaching device for removal of a mold from a cast component. The corrosion resistance system includes a container having a working fluid, such as a caustic fluid. A cast component and mold is placed within the container and a power supply is coupled to the component. During operation of the corrosion resistance system the cast component can be configured as an anode or as a cathode to provide for anodic or cathodic corrosion resistance. In one form the power supply is connected with an electrical conductor to the container and the cast component placed in electrical coupling with the container. An inert gas purge can supply an inert gas to the container. A vacuum pump can be used to remove gas from the container. Furthermore, an oxygen getter can be used in some embodiments.

1 . An apparatus comprising:
 a vessel containing a ceramic leaching material;   a metallic alloy component coupled with a ceramic core and at least partially immersed within the ceramic leaching material;   a phase change transition device capable of boiling the ceramic leaching material to assist in removing the ceramic core from the metallic alloy component;   a power device in electrical communication with the metallic alloy component and having an anode and a cathode; and   wherein a protective electrolytic cell is formed that includes the ceramic leaching material and the metallic alloy component, the protective electrolytic cell discouraging material attack of the metallic alloy component.   
     
     
         2 . The apparatus of  claim 1 , wherein the metallic alloy component is an anode of the electrolytic cell. 
     
     
         3 . The apparatus of  claim 1 , wherein the metallic alloy component is a cathode of the electrolytic cell. 
     
     
         4 . The apparatus of  claim 1 , wherein the ceramic core is part of a ceramic mold having a shell. 
     
     
         5 . The apparatus of  claim 1 , which further includes an electric conductor connected between the vessel and the metallic alloy component. 
     
     
         6 . The apparatus of  claim 1 , wherein the phase change transition device includes the capability to place the ceramic leaching material in a superheated state by varying the pressure of the ceramic leaching material. 
     
     
         7 . An apparatus comprising:
 a cast alloy structure having an casting core;   a vessel containing a caustic fluid used to leach the casting core and capable of transitioning between a liquid state and a vapor state, the state transition operable to sweep away depleted caustic fluid and replenish the caustic fluid in the vicinity of the casting core, the vessel in electrical conductive communication with the cast alloy structure;   an electrical power source capable of driving an electrochemical process and producing ions in the caustic fluid to alleviate a corrosion of the cast alloy structure.   
     
     
         8 . The apparatus of  claim 7 , wherein the electric power source is driven to provide cathodic protection of the cast alloy structure. 
     
     
         9 . The apparatus of  claim 7 , wherein the electric power source is driven to provide anodic protection of the cast alloy structure. 
     
     
         10 . The apparatus of  claim 7 , wherein the cast alloy structure is made of a material with a relatively higher electrochemical potential than the vessel. 
     
     
         11 . The apparatus of  claim 7 , which further includes an inert gas supply for delivering inert gas to the vessel and a gas withdrawal pump for extracting gas from the vessel. 
     
     
         12 . The apparatus of  claim 7 , wherein the electrical power source is connected with an electrode in contact with the caustic fluid. 
     
     
         13 . An apparatus comprising:
 a metallic cast article coupled with a leachable ceramic device used to shape the metallic cast article;   a container having a leaching material within which the metallic cast article and leachable ceramic device is disposed;   means for protecting the metallic cast article during a leaching of the leachable ceramic device, the means in electrical communication with the metallic cast article via the container.   
     
     
         14 . The apparatus of  claim 13 , wherein the means can be driving to a potential that places the metallic cast article in a passive range of an active-passive corrosion property. 
     
     
         15 . The apparatus of  claim 13 , wherein during operation of the means, the means includes a potential that provides cathodic protection of the metallic cast article. 
     
     
         16 . A method comprising:
 dispensing a leaching material within a leaching vessel;   disposing a portion of a cast alloy part within the leaching vessel and exposing a ceramic container coupled with the cast alloy part to the leaching material;   facilitating a state transition of the leaching material from a liquid state to a vapor state;   creating an electrolytic device that includes the leaching material by attaching a first electrical conductor to a first terminal of a power supply and coupling a second electrical conductor to a second terminal of the power supply;   applying a potential difference between the first electrical conductor and the second electrical conductor; and   alleviating a corrosion process of the cast alloy part.   
     
     
         17 . The method of  claim 16 , wherein the applying includes one of using the cast alloy part as an anode of the electrolytic device and using the cast alloy part as a cathode of the electrolytic device. 
     
     
         18 . The method of  claim 17 , which further includes connecting an electrical conductor between the vessel and the cast alloy part. 
     
     
         19 . The method of  claim 16 , which further includes superheating the leaching material. 
     
     
         20 . The method of  claim 16 , which further includes changing the pressure in the leaching vessel. 
     
     
         21 . The method of  claim 20 , wherein the changing includes one of providing an inert gas cover over the leaching material and evacuating a gas from the leaching vessel.