Method for producing tubular body

Abstract

A method for producing a tubular body includes winding ceramic fibers to form an aggregate with the ceramic fibers. The aggregate has a tubular shape. Pyrolytic carbon is vapor deposited on the aggregate to form a fiber-reinforced carbonaceous substrate. The pyrolytic carbon positioned at least on an outer surface of the fiber-reinforced carbonaceous substrate is converted to CVR-SiC by reaction with an SiO gas to form an CVR-SiC layer. CVD-SiC is deposited on a surface of the CVR-SiC layer after forming the CVR-SiC layer. An amount of silicon decreases from a boundary region to an inside of the fiber-reinforced carbonaceous substrate.

What is claimed is: 
     
         1 . A method for producing a tubular body, comprising:
 winding ceramic fibers to form an aggregate with the ceramic fibers, the aggregate having a tubular shape;   vapor depositing pyrolytic carbon on the aggregate to form a fiber-reinforced carbonaceous substrate;   converting the pyrolytic carbon located at least on an outer surface of the fiber-reinforced carbonaceous substrate to CVR-SiC by reaction with an SiO gas to form an CVR-SiC layer; and   depositing CVD-SiC on a surface of the CVR-SiC layer after forming the CVR-SiC layer, an amount of silicon decreasing from a boundary region to an inside of the fiber-reinforced carbonaceous substrate.   
     
     
         2 . A method for producing a tubular body, comprising:
 weaving strands including ceramic fibers to form an aggregate with the ceramic fibers, the aggregate having a braid form which has a hollow mesh body;   vapor depositing pyrolytic carbon on the aggregate to form a fiber-reinforced carbonaceous substrate;   converting the pyrolytic carbon positioned at least on an outer surface of the fiber-reinforced carbonaceous substrate to CVR-SiC by reaction with an SiO gas to form an CVR-SiC layer; and   depositing CVD-SiC on a surface of the CVR-SiC layer after forming the CVR-SiC layer, an amount of silicon decreasing from a boundary region to an inside of the fiber-reinforced carbonaceous substrate.   
     
     
         3 . The method according to  claim 1 ,
 wherein a mass ratio of the ceramic fibers to the fiber-reinforced carbonaceous substrate ranges from about 10% to about 50%.   
     
     
         4 . The method according to  claim 1 ,
 wherein a thickness of the fiber-reinforced carbonaceous substrate ranges from about 0.3 mm to about 2 mm.   
     
     
         5 . The method according to  claim 1 ,
 wherein the tubular body is used as a nuclear fuel cladding tube.   
     
     
         6 . The method according to  claim 1 ,
 wherein a thickness of the fiber-reinforced carbonaceous substrate ranges from about 0.3 mm to about 2 mm.   
     
     
         7 . The method according to  claim 1 ,
 wherein raw material for the ceramic fibers includes ZrC.   
     
     
         8 . The method according to  claim 2 ,
 wherein a mass ratio of the ceramic fibers to the fiber-reinforced carbonaceous substrate ranges from about 10% to about 50%.   
     
     
         9 . The method according to  claim 2 ,
 wherein a thickness of the fiber-reinforced carbonaceous substrate ranges from about 0.3 mm to about 2 mm.   
     
     
         10 . The method according to  claim 2 ,
 wherein the tubular body is used as a nuclear fuel cladding tube.   
     
     
         11 . The method according to  claim 2 ,
 wherein a thickness of the fiber-reinforced carbonaceous substrate ranges from about 0.3 mm to about 2 mm.   
     
     
         12 . The method according to  claim 2 ,
 wherein raw material for the ceramic fibers includes ZrC.