Apparatus and methods for slurry aluminide coating repair
Methods for deposition of an aluminide coating on an alloy component positioned within a coating compartment of a retort chamber are provided. According to the method, the coating compartment is purged with an inert gas via a first gas line; a positive pressure is created within the coating compartment utilizing the inert gas; the coating compartment is heated to a deposition temperature; and at least one reactant gas is introduced into the coating compartment while at the positive pressure and the deposition temperature to form an aluminide coating on a surface of the alloy component. Retort coating apparatus are also provided.
1. A method for deposition of an aluminide coating on an alloy component positioned within a coating compartment of a retort chamber, the method comprising:
purging the coating compartment with an inert gas via a first gas line;
creating a positive pressure within the coating compartment utilizing the inert gas, wherein the positive pressure within the coating compartment is about 1.05 bar to about 2.0 bar;
heating the coating compartment to a deposition temperature; and
introducing at least one reactant gas into the coating compartment while at the positive pressure and the deposition temperature to form an aluminide coating on a surface of the alloy component.
2. The method of claim 1 , further comprising, prior to purging the coating compartment:
placing the alloy component within the coating compartment of the retort chamber; and
thereafter, closing the coating compartment of the retort chamber with an insulated cover such that the coating compartment is atmospherically isolated.
3. The method of claim 1 , further comprising:
controlling the positive pressure within the coating compartment with a pressure control system, wherein the pressure control system comprises: at least one gas inlet and associated inlet valve; and an exhaust outlet and associated outlet valve.
4. The method of claim 3 , wherein the outlet valve is a release valve configured to exhaust gas from the coating compartment at a predetermined pressure.
5. The method of claim 1 , wherein the positive pressure within the coating compartment is about 1.1 bar to about 1.5 bar.
6. The method of claim 1 , wherein the deposition temperature of about 650° C. to about 1100° C.
7. The method of claim 1 , wherein heating the coating compartment is achieved using a plurality of heating elements positioned to heat the coating compartment.
8. The method of claim 7 , wherein the plurality of heating elements are positioned within furnace walls of the coating compartment.
9. The method of claim 2 , wherein the first gas line passes through an insulated cover.
10. The method of claim 3 , wherein the pressure control system is in communication with the inlet valve so as to control the pressure within the retort chamber.
11. The method of claim 3 , wherein the pressure control system is in communication with the outlet valve so as to control the pressure within the retort chamber.
12. The method of claim 11 , wherein the outlet valve is a release valve configured to exhaust gas from the coating compartment upon reaching a predetermined pressure controllable by the pressure control system.
13. The method of claim 12 , wherein the predetermined pressure is about 1.05 bar to about 2.0 bar.
14. The method of claim 12 , wherein the predetermined pressure is about 1.1 bar to about 1.5 bar.