Post deposition heat treatment of coating on substrate

Abstract

In one example, a method for forming an environmental barrier coating (EBC), thermal barrier coating (TBC), and/or abradable coating on a substrate. The method may include depositing a coating on a substrate to form an as-deposited coating, wherein the coating includes at least one of a TBC layer, an EBC layer, or an abradable coating layer; and heat treating the as-deposited coating at or above a first temperature for a first period of time following the deposition of the as-deposited coating on the substrate, wherein heat treating the as-deposited coating includes heating the as-deposited coating to or above the first temperature at a controlled heating rate, and wherein the controlled heating rate is selected such that the heat treated coating exhibits a compressive residual stress state upon cooling.

1 . A method comprising:
 depositing a coating on a substrate to form an as-deposited coating, wherein the coating includes at least one of a thermal barrier coating (TBC) layer, an environmental barrier coating (EBC) layer, or an abradable coating layer; and   heat treating the as-deposited coating at or above a first temperature for a first period of time following the deposition of the as-deposited coating on the substrate, wherein heat treating the as-deposited coating includes heating the as-deposited coating to or above the first temperature at a controlled heating rate, and wherein the controlled heating rate is selected such that the heat treated coating exhibits a compressive residual stress state upon cooling.   
     
     
         2 . The method of  claim 1 , wherein the as-deposited coating includes at least about 30 volume percent amorphous phase, and wherein the heat treated coating includes at least about 90 volume percent crystalline phase. 
     
     
         3 . The method of  claim 1 , wherein the controlled rate is greater than or equal to 0.5 degrees Celsius per minute (° C./min). 
     
     
         4 . The method of  claim 1 , wherein the controlled rate is about 1° C./min to about 15° C./min. 
     
     
         5 . The method of  claim 1 , further comprising, prior to heat treating the as-deposited coating:
 heat treating a first sample coating using a first heating rate;   determining a change in curvature for the heat treated first sample coating; and   selecting the first heating rate as the controlled heating rate based on the change in the curvature for the heat treated first sample coating.   
     
     
         6 . The method of  claim 5 , further comprising:
 heat treating a second sample coating using a second heating rate, wherein the first sample coating is substantially the same as the second sample coating prior to heat treatment; and   determining a change in curvature for the heat treated second sample coating, wherein selecting the first heating rate as the controlled heating rate based on the change in the curvature for the heat treated first sample coating comprises selecting the first heating rate as the controlled heating rate based on a comparison of the change in curvature for the heat treated first sample coating and the change in curvature for the heat treated second sample coating.   
     
     
         7 . The method of  claim 1 , wherein depositing the coating on the substrate to form the as-deposited coating comprises depositing the coating on the substrate via at least one of thermal spray deposition or slurry deposition. 
     
     
         8 . The method of  claim 1 , wherein the coating includes at least one of rare earth (RE) monosilicate or RE disilicate. 
     
     
         9 . The method of  claim 1 , wherein the heat-treated coating includes the EBC on the substrate and the abradable layer on the EBC. 
     
     
         10 . The method of  claim 1 , wherein the controlled heating rate is selected such that the heat treated coating exhibits a target compressive residual stress state upon cooling. 
     
     
         11 . The method of  claim 1 , wherein the controlled heating rate is selected such that the heat treated coating exhibits an increased compressive residual stress state upon cooling compared to the as-deposited coating. 
     
     
         12 . A system comprising:
 a deposition device configured to deposit a coating on a substrate to form an as-deposited coating, wherein the coating includes at least one of a thermal barrier coating (TBC) layer, an environmental barrier coating (EBC) layer, or an abradable coating layer;   a furnace configured to heat the as-deposited coating following deposition of the as-deposited coating by the deposition device; and   a controller device configured to control the heat treatment of the as-deposited coating at or above a first temperature for a first period of time following the deposition of the as-deposited coating on the substrate, wherein heat treating the as-deposited coating includes heating the as-deposited coating to or above the first temperature at a controlled heating rate, and wherein the controlled heating rate is selected such that the heat treated coating exhibits a compressive residual stress state upon cooling.   
     
     
         13 . The system of  claim 12 , wherein the as-deposited coating includes at least about 30 volume percent amorphous phase, and wherein the heat treated coating includes at least about 90 volume percent crystalline phase. 
     
     
         14 . The system of  claim 12 , wherein the controlled rate is greater than or equal to 0.5 degrees Celsius per minute (° C./min). 
     
     
         15 . The system of  claim 12 , wherein the controlled rate is about 1° C./min to about 15° C./min. 
     
     
         16 . The system of  claim 12 , further comprising, prior to heat treating the as-deposited coating:
 heat treating a first sample coating using a first heating rate;   determining a change in curvature for the heat treated first sample coating; and   selecting the first heating rate as the controlled heating rate based on the change in the curvature for the heat treated first sample coating.   
     
     
         17 . The system of  claim 16 , further comprising:
 heat treating a second sample coating using a second heating rate, wherein the first sample coating is substantially the same as the second sample coating prior to heat treatment; and   determining a change in curvature for the heat treated second sample coating, wherein selecting the first heating rate as the controlled heating rate based on the change in the curvature for the heat treated first sample coating comprises selecting the first heating rate as the controlled heating rate based on a comparison of the change in curvature for the heat treated first sample coating and the change in curvature for the heat treated second sample coating.   
     
     
         18 . The system of  claim 12 , wherein depositing the coating on the substrate to form the as-deposited coating comprises depositing the coating on the substrate via at least one of thermal spray deposition or slurry deposition. 
     
     
         19 . The system of  claim 12 , wherein the coating includes at least one of rare earth (RE) monosilicate or RE disilicate. 
     
     
         20 . The system of  claim 12 , wherein the heat-treated coating includes the EBC on the substrate and the abradable layer on the EBC.