Vapor deposition process and apparatus therefor

Abstract

An apparatus for depositing a ceramic coating on a component. The apparatus is configured to make use of an evaporation source containing multiple different oxide compounds, in which at least one of the oxide compounds has a vapor pressure that is higher than the remaining oxide compounds. The apparatus is operable to introduce the evaporation source into a coating chamber, suspend the component near the evaporation source, and project a high-energy beam on the evaporation source to melt and form a vapor cloud having a composition comprising the oxide compounds of the evaporation source. The apparatus includes a feature that prevents the vapor cloud from contacting and condensing on the component during an initial phase of operation, and subsequently permit and then again prevent the vapor cloud from contacting and condensing on the component during subsequent phases of operation in response to changes in the composition of the vapor cloud.

1 . An apparatus for depositing a ceramic coating on a surface of a component, the apparatus comprising:
 a single evaporation source containing multiple different oxide compounds, at least one of the oxide compounds having a vapor pressure that is higher than the remaining oxide compounds;   means for introducing the evaporation source into a coating chamber that suspends the component near the evaporation source;   means for projecting a high-energy beam on the evaporation source to melt the evaporation source, form a molten pool of the oxide compounds of the evaporation source, and form a vapor cloud having a composition comprising the oxide compounds of the evaporation source;   a maneuverable barrier that is maneuverable between a first position in which the barrier is between the component and the molten pool and a second position in which the barrier is withdrawn from between the component and the molten pool, wherein in the first position the barrier prevents the vapor cloud from contacting and condensing on the component and wherein in the second position the barrier allows the vapor cloud to contact and condense on the component to form the coating;   means for sensing a chemistry of the composition of the vapor cloud; and   automation responsive to changes in the chemistry of the composition of the vapor cloud sensed by the sensing means, the automation positioning the barrier in the first position if the chemistry of the composition of the vapor cloud is different from the evaporation source.   
     
     
         2 . (canceled) 
     
     
         3 . An apparatus according to  claim 1 , wherein the at least one oxide compound is selected from the group consisting of ceria, magnesia, strontia, barium oxide, lanthana, neodymia, gadolinium oxide, dysprosia, ytterbia and tantala. 
     
     
         4 . An apparatus according to  claim 3 , wherein the evaporation source consists essentially of yttria, zirconia and the at least one oxide compound. 
     
     
         5 . An apparatus according to  claim 4 , wherein the at least one oxide compound is ceria. 
     
     
         6 . An apparatus according to  claim 1 , wherein the evaporation source consists essentially of yttria, zirconia and the at least one oxide compound. 
     
     
         7 . An apparatus according to  claim 1 , wherein the at least one oxide compound is ceria. 
     
     
         8 . An apparatus according to  claim 1 , wherein the evaporation source contains about 10 to about 20 weight percent ceria, the balance essentially zirconia stabilized by about 3 to about 8 weight percent yttria. 
     
     
         9 . (canceled) 
     
     
         10 . An apparatus according to  claim 1 , wherein the automation positions the barrier in the second position if the chemistry of the composition of the vapor cloud is approximately equal to the evaporation source.