Flexible insulation blanket having a ceramic matrix composite outer layer

Abstract

A flexible insulation blanket having a ceramic matrix composite (CMC) outer layer, and a method of producing a flexible insulation blanket having a smooth, aerodynamically suitable, outer surface by infiltrating ceramic material within the outer ceramic fabric layer of the flexible insulation blanket and curing the ceramic material to form a CMC layer. The CMC layer is cured while the blanket is under compression such that the resulting CMC layer has a smooth surface.

What is claimed is:  
     
         1 . A flexible insulation blanket having an outer ceramic matrix composite layer with a smooth surface, said blanket comprising: 
 an outer ceramic matrix composite (CMC) layer comprised of 
 a ceramic fabric;  
 a ceramic matrix material incorporated in and around the fibers of the ceramic fabric;  
   an inner ceramic fabric layer; and,    a batting layer provided between the outer and inner layers;    wherein the outer layer, batting, and inner layer are quilted together to form a unitary blanket.    
     
     
         2 . The blanket of  claim 1 , wherein the outer ceramic fabric is comprised of multiple plies of fabric.  
     
     
         3 . The blanket of  claim 1 , wherein the ceramic fabric is woven from aluminoborosilicate, alumina, mullite, and silicon carbide.  
     
     
         4 . The blanket of  claim 3 , wherein the outer ceramic fabric layer is woven from an aluminoborosilicate fiber.  
     
     
         5 . The blanket of  claim 1 , wherein the outer ceramic fabric layer has a thickness of about 0.01 inches to 0.06 inches.  
     
     
         6 . The blanket of  claim 1 , wherein the batting is composed of ceramic selected from alumina, silica, mullite, zirconia, or a combination thereof.  
     
     
         7 . The blanket of  claim 1 , wherein the inner ceramic fabric is woven from fibers selected from aluminoborosilicate, alumina, mullite, S-glass, and E-glass.  
     
     
         8 . The blanket of  claim 1 , wherein the ceramic matrix material contains an emissivity agent.  
     
     
         9 . The blanket of  claim 8 , wherein the emissivity agent is SiC.  
     
     
         10 . The blanket of  claim 1 , wherein the edges of the outer fabric layer are turned toward the inner surface of the blanket such that the edges of the outer fabric layer cover at least a portion of the edge of the blanket.  
     
     
         11 . The blanket of  claim 1 , wherein the ceramic matrix material is aluminum silicate, alumina, silica, mullite, cordierite, silicon carbide, silicon nitride and black glass.  
     
     
         12 . A method of producing a flexible insulation blanket having a ceramic matrix composite infiltrated layer with a smooth surface, said method comprising: 
 layering, respectively, an outer ceramic fabric layer, a batting layer, and a inner ceramic fabric layer;    quilting said layers to form a flexible insulation blanket;    infiltrating said outer fabric layer of said blanket with a pre-ceramic slurry;    compressing the blanket in the direction of thickness of the blanket by applying pressure to said outer layer of the blanket with a smoothly surfaced plate;    curing said pre-ceramic slurry; and    sintering the infiltrated outer ceramic layer to form a ceramic matrix composite layer.    
     
     
         13 . The method of  claim 12 , wherein the outer ceramic fabric layer is comprised of multiple plies of fabric.  
     
     
         14 . The method of  claim 12 , wherein the ceramic fiber is selected from aluminoborosilicate, alumina, mullite and silicon carbide.  
     
     
         15 . The method of  claim 14 , wherein the outer ceramic fabric layer is woven from an aluminoborosilicate fiber.  
     
     
         16 . The method of  claim 12 , wherein the outer ceramic fabric layer has a thickness of about 0.01 inches to 0.06 inches.  
     
     
         17 . The method of  claim 12 , wherein the batting is composed of ceramic selected from alumina, silica, mullite, zirconia, or a combination thereof.  
     
     
         18 . The method of  claim 12 , wherein the inner ceramic fiber layer is woven from fibers selected from aluminoborosilicate, alumina, and mullite, S-glass, and E-glass.  
     
     
         19 . The method of  claim 12 , wherein the pre-ceramic slurry is infiltrated within the outer fabric layer of the blanket by soaking the fabric within the slurry.  
     
     
         20 . The method of  claim 12 , wherein the pre-ceramic slurry is infiltrated within the outer fabric layer of the blanket by applying the slurry by brushing, spraying, or sponging.  
     
     
         21 . The method of  claim 12 , wherein the pre-ceramic slurry is a suspension of 
 aluminum silicate,    a thermoplastic resin, and    a solvent selected from acetone and alcohol.    
     
     
         22 . The method of  claim 12 , wherein said slurry has a ceramic component and a solvent component, and wherein the method further comprises the step of allowing the solvent component of the pre-ceramic slurry to evaporate, resulting in a slurry with a paste-like consistency, prior to compression of the blanket.  
     
     
         23 . The method of  claim 12 , further comprising the step of applying a releasing agent to the outer surface of the infiltrated fabric layer prior to compressing the blanket.  
     
     
         24 . The method of  claim 12 , wherein the step of curing the pre-ceramic slurry occurs between about 100° F. and about 350° F.  
     
     
         25 . The method of  claim 12 , wherein the step of sintering the ceramic matrix occurs at between about 400° F. and 1200° F. for a time period of about 1 hour to 5 hours.  
     
     
         26 . The method of  claim 25 , wherein the step of sintering occurs at a temperature about 1000° F. for about 2 hours.  
     
     
         27 . The method of  claim 12 , further comprising the step of turning the edges of the fabric layer toward the inner surface of the blanket such that the edges of the outer fabric layer cover at least a portion of the edge of the blanket.  
     
     
         28 . The method of  claim 12 , further comprising releasing said compression between said curing and sintering steps.  
     
     
         29 . A method of constructing a ceramic matrix composite (CMC) infiltrated flexible insulation blanket having a smooth surface, comprising: 
 laminating an outer ceramic fabric layer, a batting layer, and a inner ceramic fabric layer;    sewing the laminate to form a quilted blanket having an outer surface corresponding to the outer fabric layer and an inner surface corresponding to the inner fabric layer;    applying an uncured ceramic matrix material to the outer surface of the blanket;    placing the blanket under pressure in the direction of thickness of the blanket;    curing said ceramic matrix material to form a CMC layer with the outer fabric layer of the blanket;    releasing said pressure; and    sintering the CMC layer of the blanket.