The disclosure describes techniques for infiltrating a CMC substrate with a first slurry to at least partially fill at least some inner spaces of the CMC substrate, where the first slurry comprises first solid particles, drying the first slurry to form an infiltrated CMC including the first solid particles, depositing a second slurry including a carrier material and second solid particles on a surface of the infiltrated CMC, where the second solid particles comprise a plurality of fine ceramic particles, a plurality of coarse ceramic particles, and a plurality of diamond particles, drying the second slurry to form an article having an outer surface layer comprising the second solid particles on the infiltrated CMC, and infiltrating the article with a molten infiltrant to form a composite article.

The disclosure describes techniques for infiltrating a CMC substrate with a first slurry to at least partially fill at least some inner spaces of the CMC substrate, where the first slurry comprises first solid particles, drying the first slurry to form an infiltrated CMC including the first solid particles, depositing a second slurry including a carrier material and second solid particles on a surface of the infiltrated CMC, where the second solid particles comprise a plurality of fine ceramic particles, a plurality of coarse ceramic particles, and a plurality of diamond particles, drying the second slurry to form an article having an outer surface layer comprising the second solid particles on the infiltrated CMC, and infiltrating the article with a molten infiltrant to form a composite article.

Procedure for controlling the chemical reaction in multi-layer ceramic decorations, according to interfacial and surface properties, in which the ceramic coating formulation is broken down into two separate compounds: on the one hand, a bottom layer formed by a glaze with part of the necessary oxides to obtain the ceramic effect, applied in the conventional manner over the ceramic substrate, and on the other hand, a top layer formed by an ink with the other necessary part of the oxides, applied by injection over the previous layer. The ceramic product is finished off with a firing process. This procedure has the advantage of regulating the penetration of the oxides of the top layer throughout the profile of the bottom layer, thus achieving an adequate concentration of oxides in the zone nearest to the surface, which permits optimization of the chemical reaction and thus, of the ceramic effect obtained.

Procedure for controlling the chemical reaction in multi-layer ceramic decorations, according to interfacial and surface properties, in which the ceramic coating formulation is broken down into two separate compounds: on the one hand, a bottom layer formed by a glaze with part of the necessary oxides to obtain the ceramic effect, applied in the conventional manner over the ceramic substrate, and on the other hand, a top layer formed by an ink with the other necessary part of the oxides, applied by injection over the previous layer. The ceramic product is finished off with a firing process. This procedure has the advantage of regulating the penetration of the oxides of the top layer throughout the profile of the bottom layer, thus achieving an adequate concentration of oxides in the zone nearest to the surface, which permits optimization of the chemical reaction and thus, of the ceramic effect obtained.

The disclosure describes a method for forming a surface layer of a ceramic matrix composite (CMC) article. The technique includes depositing a slurry on a surface of an infiltrated CMC. The slurry includes a carrier material, a binder, a plasticizer, and solid particles. The solid particles include a plurality of fine ceramic particles defining a fine particle average size less than about 5 micrometers. The method further includes drying the slurry to form an article having an outer surface layer that includes the solid particles on the infiltrated CMC. The method further includes machining at least a portion of the outer surface layer of the article. The method further includes infiltrating the article with a molten infiltrant to form a composite article.

The disclosure describes a method for forming a surface layer of a ceramic matrix composite (CMC) article. The technique includes depositing a slurry on a surface of an infiltrated CMC. The slurry includes a carrier material, a binder, a plasticizer, and solid particles. The solid particles include a plurality of fine ceramic particles defining a fine particle average size less than about 5 micrometers. The method further includes drying the slurry to form an article having an outer surface layer that includes the solid particles on the infiltrated CMC. The method further includes machining at least a portion of the outer surface layer of the article. The method further includes infiltrating the article with a molten infiltrant to form a composite article.

A porous ceramic structure includes a porous honeycomb structure composed primarily of cordierite, and Ce- and Zr-containing particles fixedly attached to the honeycomb structure. The Ce- and Zr-containing particles contain Ce and Zr. The Ce- and Zr-containing particles have a fixedly attached portion located inside the honeycomb structure and a protrusion contiguous with the fixedly attached portion and protruding from the honeycomb structure.

A porous ceramic structure includes a porous honeycomb structure composed primarily of cordierite, and Ce- and Zr-containing particles fixedly attached to the honeycomb structure. The Ce- and Zr-containing particles contain Ce and Zr. The Ce- and Zr-containing particles have a fixedly attached portion located inside the honeycomb structure and a protrusion contiguous with the fixedly attached portion and protruding from the honeycomb structure.

A method for manufacturing a pillar-shaped honeycomb structure filter including preparing a pillar-shaped honeycomb structure having a plurality of first cells and a plurality of second cells that are alternately arranged adjacent to each other with a porous partition wall interposed therebetween; adhering ceramic particles containing 50% by mass or more in total of one or two selected from SiC and SiN to a surface of the first cells; and performing a heat-oxidation treatment on the pillar-shaped honeycomb structure in which the ceramic particles are adhered to the surface of the first cells to form a porous film comprised of the ceramic particles having an oxide film thereon so as to satisfy: (1) 0.05≤T≤0.5; (2) 0.05≤T/D50; and (3) 4≤{(W.sub.1−W.sub.0)/W.sub.0×100}/D50.

A method for manufacturing a pillar-shaped honeycomb structure filter including preparing a pillar-shaped honeycomb structure having a plurality of first cells and a plurality of second cells that are alternately arranged adjacent to each other with a porous partition wall interposed therebetween; adhering ceramic particles containing 50% by mass or more in total of one or two selected from SiC and SiN to a surface of the first cells; and performing a heat-oxidation treatment on the pillar-shaped honeycomb structure in which the ceramic particles are adhered to the surface of the first cells to form a porous film comprised of the ceramic particles having an oxide film thereon so as to satisfy: (1) 0.05≤T≤0.5; (2) 0.05≤T/D50; and (3) 4≤{(W.sub.1−W.sub.0)/W.sub.0×100}/D50.