Product formed from a ceramic material, at least part of the said product not being formed from amorphous silica and including pores and satisfying the following criteria (a), (b) and (c): (a) at least 70% by number of the said pores are frustoconical tubular pores extending substantially parallel to each other in a longitudinal direction; (b) in at least one cross-section plane, the mean size of the cross sections of the said pores is greater than 0.15 m and less than 300 m; (c) in at least one cross-section plane, at least 50% by number of the pores have a convexity index Ic of greater than 87%, the convexity index of a pore being equal to the ratio Sp/Sc of the surfaces Sp and Sc delimited by the perimeter and by the convex envelope of the said pore, respectively.

Product formed from a ceramic material, at least part of the said product not being formed from amorphous silica and including pores and satisfying the following criteria (a), (b) and (c): (a) at least 70% by number of the said pores are frustoconical tubular pores extending substantially parallel to each other in a longitudinal direction; (b) in at least one cross-section plane, the mean size of the cross sections of the said pores is greater than 0.15 m and less than 300 m; (c) in at least one cross-section plane, at least 50% by number of the pores have a convexity index Ic of greater than 87%, the convexity index of a pore being equal to the ratio Sp/Sc of the surfaces Sp and Sc delimited by the perimeter and by the convex envelope of the said pore, respectively.

The preparation of ceramic matrix composite (CMCs) is disclosed in which a ceramic matrix composite (CMC) preform is made with one or more integrated core inserts made of a fugitive material comprising graphite and polyvinyl butyral. The preform with integrated core inserts is subjected to a heat treatment to remove the polyvinyl butyral (e.g., by melting or burning) while retaining the graphite. Removal of the polyvinyl butyral results in formation of one or more internal cavities within the preform in which the retained graphite aids in maintaining the shape of the internal cavities. The preform can then be subjected to densification to form a composite and the remaining graphite can be removed from the internal cavities.

The preparation of ceramic matrix composite (CMCs) is disclosed in which a ceramic matrix composite (CMC) preform is made with one or more integrated core inserts made of a fugitive material comprising graphite and polyvinyl butyral. The preform with integrated core inserts is subjected to a heat treatment to remove the polyvinyl butyral (e.g., by melting or burning) while retaining the graphite. Removal of the polyvinyl butyral results in formation of one or more internal cavities within the preform in which the retained graphite aids in maintaining the shape of the internal cavities. The preform can then be subjected to densification to form a composite and the remaining graphite can be removed from the internal cavities.

The preparation of ceramic matrix composite (CMCs) is disclosed in which a ceramic matrix composite (CMC) preform is made with one or more integrated polymer core inserts made of a fugitive material containing polyvinyl butyral. The preform with integrated polymer core inserts to a heat treatment to remove the one or more polymer core inserts (e.g., by melting or burning). Removal of the polymer core inserts forms one or more internal cavities within the composite, which can then be subjected to densification.

The preparation of ceramic matrix composite (CMCs) is disclosed in which a ceramic matrix composite (CMC) preform is made with one or more integrated polymer core inserts made of a fugitive material containing polyvinyl butyral. The preform with integrated polymer core inserts to a heat treatment to remove the one or more polymer core inserts (e.g., by melting or burning). Removal of the polymer core inserts forms one or more internal cavities within the composite, which can then be subjected to densification.

The preparation of ceramic matrix composite (CMCs) is disclosed in which a ceramic matrix composite (CMC) preform is made with one or more integrated polymer core inserts having a base structure made of a fugitive material comprising polyvinyl butyral (PVB), and one or more flow modification elements made of a non-fugitive material. The preform with integrated polymer core inserts is subjected to a heat treatment to remove the PVB base structure made of the one or more polymer core inserts (e.g., by melting or burning) while retaining the one or more flow modification elements. Removal of the PVB base structure forms one or more internal cavities within the composite with the one or more flow modification elements positioned therein. The preform can then be subjected to densification to form the CMC.

The preparation of ceramic matrix composite (CMCs) is disclosed in which a ceramic matrix composite (CMC) preform is made with one or more integrated polymer core inserts having a base structure made of a fugitive material comprising polyvinyl butyral (PVB), and one or more flow modification elements made of a non-fugitive material. The preform with integrated polymer core inserts is subjected to a heat treatment to remove the PVB base structure made of the one or more polymer core inserts (e.g., by melting or burning) while retaining the one or more flow modification elements. Removal of the PVB base structure forms one or more internal cavities within the composite with the one or more flow modification elements positioned therein. The preform can then be subjected to densification to form the CMC.

The preparation of ceramic matrix composite (CMCs) is disclosed in which a ceramic matrix composite (CMC) preform is made with one or more integrated core inserts having a base structure made of a fugitive material comprising graphite and polyvinyl butyral, and one or more flow modification elements made of a non-fugitive material. The preform with integrated core inserts is subjected to a heat treatment to remove the polyvinyl butyral (e.g., by melting or burning) while retaining the graphite and the one or more flow modification elements. Removal of the polyvinyl butyral results in formation of one or more internal cavities, with the one or more flow modification elements positioned therein, in the preform in which the retained graphite aids in maintaining the shape of the internal cavities. The preform can then be subjected to densification to form a composite and the remaining graphite can be removed from the internal cavities.

The preparation of ceramic matrix composite (CMCs) is disclosed in which a ceramic matrix composite (CMC) preform is made with one or more integrated core inserts having a base structure made of a fugitive material comprising graphite and polyvinyl butyral, and one or more flow modification elements made of a non-fugitive material. The preform with integrated core inserts is subjected to a heat treatment to remove the polyvinyl butyral (e.g., by melting or burning) while retaining the graphite and the one or more flow modification elements. Removal of the polyvinyl butyral results in formation of one or more internal cavities, with the one or more flow modification elements positioned therein, in the preform in which the retained graphite aids in maintaining the shape of the internal cavities. The preform can then be subjected to densification to form a composite and the remaining graphite can be removed from the internal cavities.