Plasma spray physical vapor deposition deposited environmental barrier coating

Abstract

A technique may include controlling, by a computing device, a vacuum pump to evacuate a vacuum chamber to high vacuum. The technique also may include controlling, by the computing device, a coating material source to provide a coating material to a plasma spray device, the coating material having a first composition including a first amount of a metal oxide and a second amount of silica. The second amount of silica may be greater than an amount of silica in a metal silicate including the first amount of metal oxide. The technique further may include controlling, by the computing device, the plasma spray device to deposit an environmental barrier coating on a substrate in the vacuum chamber using plasma spray physical vapor deposition, wherein the coating comprises the metal silicate.

1 . A system comprising:
 a vacuum pump;   a vacuum chamber;   a plasma spray device;   a coating material source; and   a computing device operable to:
 control the vacuum pump to evacuate the vacuum chamber to high vacuum; 
 control the coating material source to provide a coating material to the plasma spray device, the coating material having a first composition including a first amount of a metal oxide and a second amount of silica, wherein the second amount of silica is greater than an amount of silica in a metal silicate including the first amount of metal oxide; and 
 control the plasma spray device to deposit an environmental barrier coating on a substrate in the vacuum chamber using plasma spray physical vapor deposition, 
   wherein the coating comprises the metal silicate.   
     
     
         2 . The system of  claim 1 , wherein the metal oxide comprises at least one of alumina, barium oxide, strontium oxide, or a rare earth oxide. 
     
     
         3 . The system of  claim 1 , wherein the metal oxide comprises a rare earth oxide, and wherein the metal silicate comprises at least one of a rare earth monosilicate or a rare earth disilicate. 
     
     
         4 . The system of  claim 3 , wherein the coating material further comprises alumina, and wherein the environmental barrier coating further comprises alumina. 
     
     
         5 . The system of  claim 1 , wherein the computing device is configured to control the plasma spray device to deposit the environmental barrier coating with a substantially dense microstructure. 
     
     
         6 . The system of  claim 1 , wherein the computing device is configured to control the plasma spray device to deposit the environmental barrier coating with a columnar microstructure. 
     
     
         7 . The system of  claim 1 , wherein the computing device is configured to control the plasma spray device to deposit a first layer of the environmental barrier coating with a substantially dense microstructure and a second layer of the environmental barrier coating with a columnar microstructure. 
     
     
         8 . The system of  claim 1 , wherein the environmental barrier coating is deposited on at least one surface of the substrate that is not in a line-of-sight relationship with the plasma spray gun. 
     
     
         9 . A method comprising:
 controlling, by a computing device, a vacuum pump to evacuate a vacuum chamber to high vacuum;   controlling, by the computing device, a coating material source to provide a coating material to a plasma spray device, the coating material having a first composition including a first amount of a metal oxide and a second amount of silica, wherein the second amount of silica is greater than an amount of silica in a metal silicate including the first amount of metal oxide; and   controlling, by the computing device, the plasma spray device to deposit an environmental barrier coating on a substrate in the vacuum chamber using plasma spray physical vapor deposition, wherein the environmental barrier coating comprises the metal silicate.   
     
     
         10 . The method of  claim 9 , wherein the metal oxide comprises at least one of alumina, barium oxide, strontium oxide, or a rare earth oxide. 
     
     
         11 . The method of  claim 9 , wherein the metal oxide comprises a rare earth oxide, and wherein the metal silicate comprises at least one of a rare earth monosilicate or a rare earth disilicate. 
     
     
         12 . The method of  claim 11 , wherein the coating material further comprises alumina, and wherein the environmental barrier coating further comprises alumina. 
     
     
         13 . The method of  claim 9 , wherein the computing device is configured to control the plasma spray device to deposit the environmental barrier coating with at least one of a substantially dense microstructure or a columnar microstructure. 
     
     
         14 . The method of  claim 9 , wherein the computing device is configured to control the plasma spray device to deposit a first layer of the environmental barrier coating with a substantially dense microstructure and a second layer of the environmental barrier coating with a columnar microstructure. 
     
     
         15 . The method of  claim 9 , wherein the environmental barrier coating is deposited on at least one surface of the substrate that is not in a line-of-sight relationship with the plasma spray gun. 
     
     
         16 . A computer readable storage device comprising instructions that, when executed, cause a computing device to:
 control a vacuum pump to evacuate a vacuum chamber to high vacuum;   control a coating material source to provide a coating material to a plasma spray device, the coating material having a first composition including a first amount of a metal oxide and a second amount of silica, wherein the second amount of silica is greater than an amount of silica in a metal silicate including the first amount of metal oxide; and   control the plasma spray device to deposit an environmental barrier coating on a substrate in the vacuum chamber using plasma spray physical vapor deposition, wherein the coating comprises the metal silicate.   
     
     
         17 . The computer readable storage device of  claim 16 , wherein the metal oxide comprise a rare earth oxide, and wherein the metal silicate comprises at least one of a rare earth monosilicate or a rare earth disilicate. 
     
     
         18 . The computer readable storage device of  claim 16 , wherein the instructions, when executed, cause the computing device to control the plasma spray device to deposit the environmental barrier coating with at least one of a substantially dense microstructure or a columnar microstructure. 
     
     
         19 . The computer readable storage device of  claim 16 , wherein the instructions, when executed, cause the computing device to control the plasma spray device to deposit a first layer of the environmental barrier coating with a substantially dense microstructure and a second layer of the environmental barrier coating with a columnar microstructure. 
     
     
         20 . The computer readable storage device of  claim 16 , wherein the instructions, when executed, cause the computing device to control the plasma spray device the environmental barrier coating on at least one surface of the substrate that is not in a line-of-sight relationship with the plasma spray gun.