Method for microstructure control of ceramic thermal spray coating

Abstract

An apparatus for applying segmented ceramic coatings includes means for supporting and moving one or more substrates; one or more heat sources disposed proximate to one or more substrates, wherein at least one of the heat sources is positioned to apply a heat stream to pre-heat a thermal gradient zone on a surface of a substrate; a material deposition device disposed proximate to one or more heat sources, wherein the material deposition device is positioned to deposit a material on a deposition area located behind the thermal gradient zone on the surface; and means for monitoring a surface temperature of one or more substrates.

1 . A method of forming a segmented ceramic spray coating on a substrate, comprising:
 (1) providing one or more heat sources disposed proximate to a substrate;   (2) depositing optionally a quantity of a bond coat material into a heat stream of said one or more heat sources and onto a deposition area of a surface of said substrate to form an optional bond coat layer;   (3) depositing optionally a quantity of a first ceramic material into said heat stream of said one or more heat sources and onto said deposition area of said surface to form an optional first ceramic material layer upon said optional bond coat layer;   (4) applying said heat stream to a preheated thermal gradient zone located in front of said deposition area of a surface of said first ceramic material layer to expand said optional first ceramic material;   (5) depositing one or more quantities of additional ceramic material into said heat stream and upon said pre-heated, expanded optional first ceramic material layer to form one or more additional layers of ceramic material;   (6) cooling said one or more additional layers of ceramic materials to promote vertical crack propagation therein; and   (7) applying said heat stream to said pre-heated thermal gradient zone of a surface of said one or more additional layers of ceramic material to expand said additional ceramic material.   
     
     
         2 . The method of  claim 1 , wherein steps 5 through 7 are repeated one or more times. 
     
     
         3 . The method of  claim 1 , wherein applying said heat stream comprises applying said heat stream using one or more heat sources. 
     
     
         4 . The method of  claim 3 , wherein applying said heat stream comprises applying said heat stream using two heat sources. 
     
     
         5 . The method of  claim 1 , further comprising monitoring a temperature of said first ceramic material layer and said one or more additional layers of ceramic material. 
     
     
         6 . An apparatus for applying segmented ceramic coatings, comprising:
 means for supporting and moving at least one substrate;   means for promoting vertical crack propagation by equilibrating a thermal gradient between said at least one substrate or at least one segmented ceramic coating layer or both said at least one substrate and said at least one segmented ceramic coating layer and at least one vertically cracking ceramic material coating layer being deposited; and   means for monitoring a surface temperature of said at least one substrate.   
     
     
         7 . The apparatus of  claim 21 , wherein said at least one heat source comprise at least one of: a torch, a radiant heat source, a convective heat source, and a laser emitting heat source. 
     
     
         8 . The apparatus of  claim 21 , wherein said at least one heat source comprise a torch and a second heat source comprising at least one of: a radiant heat source, a convective heat source, and a laser emitting heat source. 
     
     
         9 . The apparatus of  claim 21 , wherein said at least one heat source comprise a first heat source comprising at least one of: a radiant heat source, a convective heat source, and a laser emitting heat source; and a second heat source comprising at least one of: a radiant heat source, a convective heat source, and a laser emitting heat source. 
     
     
         10 . The apparatus of  claim 21 , wherein said material deposition device comprises a ceramic material deposition device. 
     
     
         11 . The apparatus of  claim 21 , wherein said material deposition device comprises a bond coat material deposition device. 
     
     
         12 . The apparatus of  claim 21 , wherein said material deposition device is capable of depositing more than one type of material. 
     
     
         13 . The apparatus of  claim 12 , wherein said more than one type of material comprises a ceramic material and a bond coat material. 
     
     
         14 . The apparatus of  claim 6 , wherein said means for supporting and moving said at least one substrate is capable of moving said at least one substrate in a first direction and said material deposition device is designed to deposit a quantity of material onto said at least one substrate in a second direction with respect to said at least one substrate. 
     
     
         15 . The apparatus of  claim 14 , wherein said first direction is the same or opposite said second direction. 
     
     
         16 . The apparatus of  claim 6 , wherein said means for supporting and moving said at least one substrate is capable of moving said at least one substrate in a first direction and said one or more heat sources are capable of moving in a third direction with respect to said at least one substrate. 
     
     
         17 . The apparatus of  claim 16 , wherein said third direction is opposite said first direction. 
     
     
         18 . The apparatus of  claim 21 , wherein said material deposition device is designed to deposit a quantity of material onto said at least one substrate in a second direction and said at least one heat source is capable of moving in a third direction with respect to said material deposition device. 
     
     
         19 . The apparatus of  claim 18 , wherein said second direction is the same or opposite said third direction. 
     
     
         20 . The apparatus of  claim 6 , wherein said means for monitoring comprises at least one of: an infrared camera, an optical pyrometer, and a thermocouple. 
     
     
         21 . The apparatus of  claim 6 , wherein said means for equilibrating comprises:
 at least one heat source is disposed proximate to said one or more substrates, wherein said at least one heat source is positioned to apply a heat stream to pre-heat a thermal gradient zone on a surface of said at least one substrate and establish a temperature and a thermal gradient between said at least one substrate and said at least one material coating layer being deposited; and   a material deposition device disposed proximate to said at least one heat source, wherein said material deposition device is positioned to deposit a material on a deposition area located behind said thermal gradient zone on said surface.