Process for producing ceramic fiber-reinforced composite material and ceramic fiber-reinforced composite material

Abstract

To obtain a ceramic fiber-reinforced composite material, by melt-infiltrating a composite material substrate obtained by forming ceramic fibers into a composite with a matrix formed of an inorganic substance, with an alloy having a composition that is constituted by a disilicate of at least one or more transition metal among transition metals that belong to Group 3A, Group 4A or Group 5A of the Periodic Table and silicon as the remainder, and having the silicon content ratio of 66.7 at % or more.

What is claimed is: 
     
         1 . A process for producing a ceramic fiber-reinforced composite material that is formed by infiltrating the entirety or a part of pores that are present in a composite material substrate obtained by forming ceramic fibers into a composite with a matrix formed of an inorganic substance, with an infiltrating material,
 wherein the infiltrating material is an alloy having a composition that is constituted by a disilicate of at least one or more transition metal among transition metals selected from scandium, yttrium, titanium, zirconium, hafnium, vanadium, niobium and tantalum belonging to Group 3A, Group 4A or Group 5A of the Periodic Table and silicon as the remainder, has a silicon content ratio (including the silicon in the transition metal disilicate) of 66.7 at % or more, and gives a melting point that is lower than that of a single body of silicon, and   the process comprises melt-infiltrating the pores that are present in the composite material substrate with the infiltrating material under a temperature environment at a temperature equal to or more than the melting point of the alloy as the infiltrating material.   
     
     
         2 . The process for producing a ceramic fiber-reinforced composite material according to  claim 1 , comprising:
 providing the entirety or a part of the pores that are present in the composite material substrate with free carbon prior to the melt infiltration; and   reacting the alloy as the infiltrating material and the free carbon in the pores during the melt infiltration to generate silicon carbide and a carbide of the transition metal.   
     
     
         3 . The process for producing a ceramic fiber-reinforced composite material according to  claim 1 , wherein the melting point of the residual alloy that is solidified in the pores after the melt infiltration is higher than the melting point of the alloy as the infiltrating material prior to the melt infiltration. 
     
     
         4 . The process for producing a ceramic fiber-reinforced composite material according to  claim 2 , wherein the melting point of the residual alloy that is solidified in the pores after the melt infiltration is higher than the melting point of the alloy as the infiltrating material prior to the melt infiltration. 
     
     
         5 . The process for producing a ceramic fiber-reinforced composite material according to  claim 1 , wherein the ceramic fibers are silicon carbide fibers. 
     
     
         6 . The process for producing a ceramic fiber-reinforced composite material according to  claim 2 , wherein the ceramic fibers are silicon carbide fibers. 
     
     
         7 . The process for producing a ceramic fiber-reinforced composite material according to  claim 3 , wherein the ceramic fibers are silicon carbide fibers. 
     
     
         8 . The process for producing a ceramic fiber-reinforced composite material according to  claim 4 , wherein the ceramic fibers are silicon carbide fibers. 
     
     
         9 . A ceramic fiber-reinforced composite material that is formed by infiltrating the entirety or a part of pores that are present in a composite material substrate obtained by forming ceramic fibers into a composite with a matrix formed of an inorganic substance, with an infiltrating material,
 wherein the infiltrating material is an alloy having a composition that is constituted by a disilicate of at least one or more transition metal among transition metals selected from scandium, yttrium, titanium, zirconium, hafnium, vanadium, niobium and tantalum belonging to Group 3A, Group 4A or Group 5A of the Periodic Table and silicon as the remainder, has a silicon content ratio (including the silicon in the transition metal disilicate) of 66.7 at % or more, and gives a melting point that is lower than that of a single body of silicon.   
     
     
         10 . The ceramic fiber-reinforced composite material according to  claim 9 , wherein silicon carbide and a carbide of the transition metal are present in interface regions between the pores and the infiltrating material. 
     
     
         11 . The ceramic fiber-reinforced composite material according to  claim 9 , wherein the melting point of the residual alloy that is solidified in the pores after the melt infiltration is higher than the melting point of the alloy as the infiltrating material prior to the melt infiltration. 
     
     
         12 . The ceramic fiber-reinforced composite material according to  claim 10 , wherein the melting point of the residual alloy that is solidified in the pores after the melt infiltration is higher than the melting point of the alloy as the infiltrating material prior to the melt infiltration. 
     
     
         13 . The ceramic fiber-reinforced composite material according to  claim 9 , wherein the ceramic fibers are silicon carbide fibers. 
     
     
         14 . The ceramic fiber-reinforced composite material according to  claim 10 , wherein the ceramic fibers are silicon carbide fibers. 
     
     
         15 . The ceramic fiber-reinforced composite material according to  claim 11 , wherein the ceramic fibers are silicon carbide fibers. 
     
     
         16 . The ceramic fiber-reinforced composite material according to  claim 12 , wherein the ceramic fibers are silicon carbide fibers.