Thermal spray deposited environmental barrier coating

Abstract

In one example, a method for forming an environmental barrier coating (EBC) on a substrate. The method may include depositing an environmental barrier coating (EBC) on a substrate via a thermal spray apparatus to form an as-deposited EBC; heat treating the as-deposited EBC at or above a first temperature for first period of time following the deposition of the as-deposited EBC on the substrate; and cooling the as-deposited EBC to a second temperature following the heat treatment at a controlled rate over a second period of time to form a heat-treated EBC on the substrate. The first temperature, the first period of time, the controlled rate, and the second period of time may be selected to increase a weight percent of crystalline phase in the heat-treated EBC compared to the as-deposited EBC.

1 . A method comprising:
 depositing an environmental barrier coating (EBC) on a substrate via a thermal spray apparatus to form an as-deposited EBC;   heat treating the as-deposited EBC at or above a first temperature for first period of time following the deposition of the as-deposited EBC on the substrate; and   cooling the as-deposited EBC to a second temperature following the heat treatment at a controlled rate over a second period of time to form a heat-treated EBC on the substrate, wherein the first temperature, the first period of time, the controlled rate, and the second period of time are selected to increase a weight percent of crystalline phase in the heat-treated EBC compared to the as-deposited EBC.   
     
     
         2 . The method of  claim 1 , wherein the first temperature is about 850 degrees Celsius. 
     
     
         3 . The method of  claim 1 , wherein the first temperature is about 1000 degrees Celsius to about 1200 degree Celsius. 
     
     
         4 . The method of  claim 1 , wherein the controlled rate is no greater than about 5 degrees Celsius per minute. 
     
     
         5 . The method of  claim 1 , wherein the second temperature is about 500 degrees Celsius or less. 
     
     
         6 . The method of  claim 1 , wherein the second period of time is greater than about one hour. 
     
     
         7 . The method of  claim 1 , wherein the heat-treated EBC includes at least 50 weight percent crystalline phase. 
     
     
         8 . The method of  claim 1 , wherein the as-deposited EBC includes less than 50 weight percent crystalline phase. 
     
     
         9 . The method of  claim 1 , further comprising, prior to depositing the EBC on the substrate, heating the substrate to a third temperature, wherein depositing the EBC on the substrate via the thermal spray device comprises depositing the EBC on the substrate via the thermal spray apparatus while the substrate is at the third temperature. 
     
     
         10 . The method of  claim 9 , wherein the third temperature is at least about 800 degrees Celsius. 
     
     
         11 . A system comprising:
 a thermal spray device configured to deposit an environmental barrier coating (EBC) on a substrate to form an as-deposited EBC;   a furnace configured to heat the as-deposited EBC following deposition of the as-deposited EBC by the thermal spray device; and   a computing device configured to control the thermal spray device to deposit the EBC on the substrate to form the as-deposited EBC, control the heat treatment of the as-deposited EBC at or above a first temperature for a first period of time following the deposition of the as-deposited EBC on the substrate, and control the cooling of the as-deposited EBC to a second temperature following the heat treatment at a controlled rate over a second period of time, wherein the first temperature, the first period of time, the controlled rate, and the second period of time are selected to increase a weight percent of crystalline phase in the heat-treated EBC compared to the as-deposited EBC.   
     
     
         12 . The system of  claim 11 , wherein the first temperature is about 850 degrees Celsius. 
     
     
         13 . The system of  claim 11 , wherein the first temperature is about 1000 degrees Celsius to about 1200 degree Celsius. 
     
     
         14 . The system of  claim 11 , wherein the controlled rate is no greater than about 5 degrees Celsius per minute. 
     
     
         15 . The system of  claim 11 , wherein the second temperature is about 500 degrees Celsius or less. 
     
     
         16 . The system of  claim 11 , wherein the second period of time is greater than about one hour. 
     
     
         17 . The system of  claim 11 , wherein the heat-treated EBC includes at least 50 weight percent crystalline phase. 
     
     
         18 . The system of  claim 11 , wherein the as-deposited EBC includes less than 50 weight percent crystalline phase. 
     
     
         19 . The system of  claim 11 , wherein the computing device is configured to, prior to depositing the EBC on the substrate, control heating of the substrate to a third temperature, wherein the EBC is deposited on the substrate via the thermal spray apparatus while the substrate is at the third temperature. 
     
     
         20 . The system of  claim 19 , wherein the third temperature is at least about 800 degrees Celsius.