A method for forming a high temperature coating includes applying carbon powder to a surface of a carbon/carbon (C/C) composite substrate to force the carbon powder into one or more surface voids of the surface of the C/C composite substrate. The carbon powder has a substantially same composition and morphology as a surface portion of the C/C composite substrate. The method includes applying a metal slurry to the surface of the C/C composite substrate following the application of the carbon powder and reacting a metal of the metal slurry with carbon of the carbon powder and carbon of the surface portion of the C/C composite substrate to form a metal-rich antioxidant layer of a metal carbide on the C/C composite substrate.

A method of protecting a part made of carbon-including composite material against oxidation, the method including a) applying a coating composition on at least a portion of the outside surface of the part, the coating composition being in the form of an aqueous suspension including: a metallic phosphate; a powder of a compound comprising titanium; and a B.sub.4C powder; and b) applying heat treatment to the coating composition applied during step a) with a treatment temperature lying in the range 330 C. to 730 being imposed during the heat treatment in order to obtain a coating on the outside surface of the part, the coating including a first phase in which the metallic phosphate is in crystalline form and a second phase in which the metallic phosphate is in amorphous form.

A method of protecting a part made of carbon-including composite material against oxidation, the method including a) applying a coating composition on at least a portion of the outside surface of the part, the coating composition being in the form of an aqueous suspension including: a metallic phosphate; a powder of a compound comprising titanium; and a B.sub.4C powder; and b) applying heat treatment to the coating composition applied during step a) with a treatment temperature lying in the range 330 C. to 730 being imposed during the heat treatment in order to obtain a coating on the outside surface of the part, the coating including a first phase in which the metallic phosphate is in crystalline form and a second phase in which the metallic phosphate is in amorphous form.

A compound sintered body contains cubic boron nitride particles and binder particles. The composite sintered body contains 40 vol % or more and 80 vol % or less of the cubic boron nitride particles. The binder particles contain TiCN particles. The composite sintered body shows a first peak belonging to a (200) plane of the TiCN particles in a range in which a Bragg angle 2 is 41.7 or more and 42.6 or less in an X-ray diffraction spectrum measured using a Cu-K ray as a ray source.

A compound sintered body contains cubic boron nitride particles and binder particles. The composite sintered body contains 40 vol % or more and 80 vol % or less of the cubic boron nitride particles. The binder particles contain TiCN particles. The composite sintered body shows a first peak belonging to a (200) plane of the TiCN particles in a range in which a Bragg angle 2 is 41.7 or more and 42.6 or less in an X-ray diffraction spectrum measured using a Cu-K ray as a ray source.

A cutting tool including a substrate composed of a silicon nitride-based sintered body and a coating layer. The coating layer includes first, second, third and fourth layers. The first layer is located on the surface of the substrate and is composed of TiN having an average crystalline width of 0.1 to 0.4 m. The second layer is located on the first layer and composed of Al.sub.2O.sub.3 having an average crystalline width of 0.01 to 1.5 m. The third layer is located on the second layer and is composed of TiN having an average crystalline width of 0.01 to 0.1 m which is smaller than that of the first layer. The fourth layer is located on the third layer and is composed of Al.sub.2O.sub.3 having an average crystalline width of 0.01 to 1.5 m.

A cutting tool including a substrate composed of a silicon nitride-based sintered body and a coating layer. The coating layer includes first, second, third and fourth layers. The first layer is located on the surface of the substrate and is composed of TiN having an average crystalline width of 0.1 to 0.4 m. The second layer is located on the first layer and composed of Al.sub.2O.sub.3 having an average crystalline width of 0.01 to 1.5 m. The third layer is located on the second layer and is composed of TiN having an average crystalline width of 0.01 to 0.1 m which is smaller than that of the first layer. The fourth layer is located on the third layer and is composed of Al.sub.2O.sub.3 having an average crystalline width of 0.01 to 1.5 m.

There are provided a continuous fiber-reinforced silicon carbide member and the like which allow sufficient improvement in a mechanical property and environmental resistance. The continuous fiber-reinforced silicon carbide member of an embodiment is a tubular shape and has a first composite material layer and a second composite material layer. In the first composite material layer, continuous fibers of silicon carbide are combined with a matrix of silicon carbide. In the second composite material layer, continuous fibers of carbon are combined with a matrix of silicon carbide. Then, the first composite material layer and the second composite material layer are stacked.

A cubic boron nitride sintered body including cubic boron nitride and a binder phase, wherein a content of the cubic boron nitride is 40 volume % or more and 80 volume % or less; a content of the binder phase is 20 volume % or more and 60 volume % or less; an average particle size of the cubic boron nitride is 0.5 m or more and 4.0 m or less; the binder phase contains TiC and TiB.sub.2 and contains substantially no AlN and/or Al.sub.2O.sub.3; a (101) plane of TiB.sub.2 in the binder phase shows a maximum peak position (2) in X-ray diffraction of 44.2 or more; and a (200) plane of TiC in the binder phase shows a maximum peak position (2) in X-ray diffraction of less than 42.1.

A cubic boron nitride sintered body including cubic boron nitride and a binder phase, wherein a content of the cubic boron nitride is 40 volume % or more and 80 volume % or less; a content of the binder phase is 20 volume % or more and 60 volume % or less; an average particle size of the cubic boron nitride is 0.5 m or more and 4.0 m or less; the binder phase contains TiC and TiB.sub.2 and contains substantially no AlN and/or Al.sub.2O.sub.3; a (101) plane of TiB.sub.2 in the binder phase shows a maximum peak position (2) in X-ray diffraction of 44.2 or more; and a (200) plane of TiC in the binder phase shows a maximum peak position (2) in X-ray diffraction of less than 42.1.