Assembly for controlling thermal stresses in ceramic matrix composite articles

Abstract

An assembly and method for controlling thermal stresses within ceramic-based articles when subjected to high temperatures while supported by a metallic article. The assembly includes a first body formed of a metallic material and having oppositely-disposed first and second surfaces, and a second body formed of a ceramic-based material and supported by the first body from the first surface thereof. The first and second bodies are located in a hot gas path such that the second body and the first surface of the first body are directly impinged by flowing hot gases. The assembly further includes a substantially uniform pattern of fins protruding from the second surface of the first body, and/or an interface structure between the first and second bodies that positively retains the second body to the first body and thermally insulates the first body from the first body.

1 . An assembly comprising: 
 a first body formed of a metallic material and having a first surface and an oppositely-disposed second surface;    a second body formed of a ceramic-based material and supported by the first body from the first surface thereof, the first and second bodies being located in a hot gas path such that the second body and the first surface of the first body are directly impinged by flowing hot gases; and    a substantially uniform pattern of fins protruding from the second surface of the first body, the fins being of sufficient size to increase the rigidity of the first body and promote heat transfer from the first body.    
   
   
       2 . An assembly according to  claim 1 , wherein the fins are integrally formed with the first body.  
   
   
       3 . An assembly according to  claim 1 , wherein the first body has a recess in the first surface thereof, the assembly further comprising an interface structure between the first and second bodies, the interface structure comprising a resilient sealing member received in the recess and disposed between the first and second bodies, the interface structure further comprising a ceramic saddle formed separately from the first and second bodies, received in the recess with the resilient sealing member, and disposed between the resilient sealing member and the second body.  
   
   
       4 . An assembly according to  claim 3 , wherein the ceramic saddle and the second body define a shiplap joint therebetween.  
   
   
       5 . An assembly according to  claim 3 , wherein the ceramic saddle and the resilient sealing member define a shiplap joint therebetween.  
   
   
       6 . An assembly according to  claim 3 , wherein the resilient sealing member comprises a fabric sheet material that is continuous between the vane and the platform.  
   
   
       7 . An assembly according to  claim 3 , wherein the ceramic saddle is formed of a monolithic ceramic material.  
   
   
       8 . An assembly according to  claim 1 , wherein the assembly is a nozzle segment of a gas turbine engine, the first body is a platform of the nozzle segment, and the second body is a vane of the nozzle segment.  
   
   
       9 . An assembly according to  claim 8 , further comprising a third body that supports the second body opposite the first body such that the second body is between the first and third bodies.  
   
   
       10 . An assembly comprising: 
 a first body formed of a metallic material and having a first surface, an oppositely-disposed second surface, and a recess in the first surface;    a second body formed of a ceramic-based material and supported by the first body from the first surface thereof, the first and second bodies being located in a hot gas path such that the second body and the first surface of the first body are directly impinged by flowing hot gases; and    an interface structure between the first and second bodies, the interface structure comprising a resilient sealing member received in the recess and disposed between the first and second bodies, the interface structure further comprising a ceramic saddle formed separately from the first and second bodies, received in the recess with the resilient sealing member, and disposed between the resilient sealing member and the second body.    
   
   
       11 . An assembly according to  claim 10 , wherein the ceramic saddle and the second body define a shiplap joint therebetween.  
   
   
       12 . An assembly according to  claim 10 , wherein the ceramic saddle and the resilient sealing member define a shiplap joint therebetween.  
   
   
       13 . An assembly according to  claim 10 , wherein the resilient sealing member comprises a fabric sheet material that is continuous between the vane and the platform.  
   
   
       14 . An assembly according to  claim 10 , wherein the ceramic saddle is formed of a monolithic ceramic material.  
   
   
       15 . An assembly according to  claim 10 , further comprising a substantially uniform pattern of fins protruding from the second surface of the first body, the fins being of sufficient size to increase the rigidity of the first body and promote heat transfer from the first body.  
   
   
       16 . An assembly according to  claim 10 , wherein the assembly is a nozzle segment of a gas turbine engine, the first body is a platform of the nozzle segment, and the second body is a vane of the nozzle segment.  
   
   
       17 . An assembly according to  claim 10 , further comprising a third body that supports the second body opposite the first body such that the second body is between the first and third bodies.  
   
   
       18 . A nozzle assembly of a gas turbine engine, the nozzle assembly comprising: 
 first and second platforms cast from a metallic material, each of the first and second platforms having first surfaces facing a hot gas path of the gas turbine engine so as to be directly impinged by flowing combustion gases, the first platform having a recess in the first surface thereof and integrally-cast fins protruding from a second surface thereof opposite the first surface, the fins being of sufficient size to increase the rigidity of the first platform and promote heat transfer from the first platform;    a vane formed of a ceramic matrix composite material and supported by the first and second platforms from the first surfaces thereof, the vane being located in the hot gas path such that the vane is directly impinged by the flowing combustion gases; and    an interface structure between the first platform and the vane, the interface structure comprising a resilient sealing member received in the recess in the first surface of the first platform and disposed between the first platform and the vane, the interface structure further comprising a saddle formed of a monolithic ceramic material, received in the recess with the resilient sealing member, and disposed between the resilient sealing member and the vane, the ceramic saddle and the vane defining a first shiplap joint therebetween, the ceramic saddle and the resilient sealing member defining a second shiplap joint therebetween.    
   
   
       19 . A nozzle assembly according to  claim 18 , further comprising means for impinging the second surface of the first platform with cooling air.  
   
   
       20 . A nozzle assembly according to  claim 18 , wherein the resilient sealing member comprises a fabric sheet material that is continuous between the vane and the platform.