Apparatus and methods for forming modified metal coatings

Abstract

Methods and systems for forming modified metal coatings on a gas turbine engine component. The gas turbine engine component is placed inside a container having a known volume, along with a source material containing a secondary element. The container, gas turbine engine component, and the source material inside the container are placed into an oxygen-depleted space inside a reaction chamber. At least one temperature for the source material is determined based upon the known volume of the container and an amount of the source material. While in the oxygen-depleted space, the source material is heated to the at least one temperature sufficient to release a vapor phase reactant containing the secondary element. The vapor phase reactant is confined inside the container at an approximately constant pressure and the secondary element is deposited from the vapor phase reactant as a layer on the gas turbine engine component.

What is claimed is: 
     
         1 . A deposition system comprising:
 a reaction chamber enclosing a interior space;   a vacuum pump in fluid communication with the interior space of the reaction chamber, the vacuum pump configured to evacuate the interior space so that the interior space in an oxygen-depleted state during deposition;   a heating element configured to heat the reaction chamber;   a container inside the reaction chamber and in fluid communication with the interior space, the container having an interior space of a known volume that is volumetrically smaller than the interior space of the reaction chamber, the container configured to hold a gas turbine engine component and a source material, and the container configured to maintain the interior space of the container at an approximately constant pressure; and   a controller configured to heat the source material to at least one temperature based upon the known volume of the interior space of the container and an amount of the source material to release a vapor phase reactant containing the secondary element,   wherein the vapor phase reactant is confined by the container in proximity to the gas turbine engine component.   
     
     
         2 . The deposition system of  claim 1  further comprising:
 a thermal sensor configured to sense a temperature of the container, the thermal sensor configured to supply temperature signals to the controller for adjusting the power supplied to the heating element. 
 
     
     
         3 . The deposition system of  claim 1  further comprising:
 a holder inside the container, the holder configured to hold the source material. 
 
     
     
         4 . The deposition system of  claim 3  wherein the holder is an open crucible. 
     
     
         5 . The deposition system of  claim 1  wherein the controller is configured to heat the source material to the source material to a plurality of heating levels at which the vapor phase reactant is released by vaporization. 
     
     
         6 . The deposition system of  claim 5  wherein each of the heating levels is associated with a respective one of a plurality of temperatures that progressively increase with increasing time. 
     
     
         7 . The deposition system of  claim 5  wherein the temperature at each of the plurality of heating levels is approximately isothermal. 
     
     
         8 . The deposition system of  claim 5  wherein each of the heating levels is associated with a respective one of a plurality of time intervals. 
     
     
         9 . The deposition system of  claim 5  wherein time intervals at the plurality of heating levels are approximately isochronal. 
     
     
         10 . The deposition system of  claim 1  wherein the at least one temperature for the vapor phase reactant is further based upon a target pressure of the vapor phase reactant inside the container. 
     
     
         11 . The deposition system of  claim 10  wherein the controller is configured to control the temperature of the vapor phase reactant while confining the vapor phase reactant inside the container to maintain the vapor phase reactant inside of the container approximately constant at the target pressure.