A crucible includes an outer element and an inner element. The outer element includes a first portion that is horizontal at a bottom end of the crucible and a second portion that ascends radially outwardly from the bottom end of the crucible to a top end of the crucible at a first acute angle to a vertical axis. The inner element includes a conus with a cylinder at a base of the conus. The conus descends radially outwardly from the top end of the crucible to the bottom end of the crucible at a second acute angle to the vertical axis. The inner element includes a base portion of the cylinder attached to the first portion of the outer element using a sealant to form a hollow mold between an inner portion of the outer element and an outer portion of the inner element.

An embodiment of a PCD insert comprises an embodiment of a PCD element joined to a cemented carbide substrate at an interface. The PCD element has internal diamond surfaces defining interstices between them. The PCD element comprises a masked or passivated region and an unmasked or unpassivated region, the unmasked or unpassivated region defining a boundary with the substrate, the boundary being the interface. At least some of the internal diamond surfaces of the masked or passivated region contact a mask or passivation medium, and some or all of the interstices of the masked or passivated region and of the unmasked or unpassivated region are at least partially filled with an infiltrant material.

An embodiment of a PCD insert comprises an embodiment of a PCD element joined to a cemented carbide substrate at an interface. The PCD element has internal diamond surfaces defining interstices between them. The PCD element comprises a masked or passivated region and an unmasked or unpassivated region, the unmasked or unpassivated region defining a boundary with the substrate, the boundary being the interface. At least some of the internal diamond surfaces of the masked or passivated region contact a mask or passivation medium, and some or all of the interstices of the masked or passivated region and of the unmasked or unpassivated region are at least partially filled with an infiltrant material.

A method for producing a silica composite particle including a silica particle and at least one compound in which an aluminum atom bonds to an organic group through oxygen. The method includes: (i) providing a silica particle dispersion liquid having a silica particle content of about 20 mass % or more; (ii) mixing and reacting a compound represented by formula (S1) and the silica particle dispersion liquid to obtain a slurry; (iii) providing the at least one compound; and (iv) then mixing and reacting the slurry with the at least one compound to form the silica composite particle.

A method of manufacturing a honeycomb structure, the method including: a circumferential coat layer forming process of applying a circumferential coating material on a circumferential surface of a ceramic honeycomb structure to form a circumferential coat layer, the circumferential coat layer forming process including: a rotating process of matching an axial direction of the honeycomb structure; and an applying process of discharging the circumferential coating material to apply the circumferential coating material on the circumferential surface of the honeycomb structure that rotates, wherein in the applying process, a discharge speed of the circumferential coating material, calculated by Equation (1), discharged from the discharge nozzle is 50 to 120 mm/s, and

Discharge speed V [mm/s]=Supplied amount q [g/s] of circumferential coating material(Density [g/mm.sup.3] of circumferential coating materialArea S [mm.sup.2] of discharge opening)(1).

A method of manufacturing a honeycomb structure, the method including: a circumferential coat layer forming process of applying a circumferential coating material on a circumferential surface of a ceramic honeycomb structure to form a circumferential coat layer, the circumferential coat layer forming process including: a rotating process of matching an axial direction of the honeycomb structure; and an applying process of discharging the circumferential coating material to apply the circumferential coating material on the circumferential surface of the honeycomb structure that rotates, wherein in the applying process, a discharge speed of the circumferential coating material, calculated by Equation (1), discharged from the discharge nozzle is 50 to 120 mm/s, and

Discharge speed V [mm/s]=Supplied amount q [g/s] of circumferential coating material(Density [g/mm.sup.3] of circumferential coating materialArea S [mm.sup.2] of discharge opening)(1).

The disclosure describes techniques for forming a surface layer of an article including a CMC using a cast. In some examples, the surface layer includes three-dimensional surface features, which may increase adhesion between the CMC and a coating on the CMC. In some examples, the surface layer may include excess material, with or without three-dimensional surface features, which is on the CMC. The excess material may be machined to remove some of the excess material and facilitate conforming the article to dimensional tolerances, e.g., for fitting the article to another component. The excess material may reduce a likelihood that the CMC (e.g., reinforcement material in the CMC) is damaged by the machining.

The disclosure describes techniques for forming a surface layer of an article including a CMC using a cast. In some examples, the surface layer includes three-dimensional surface features, which may increase adhesion between the CMC and a coating on the CMC. In some examples, the surface layer may include excess material, with or without three-dimensional surface features, which is on the CMC. The excess material may be machined to remove some of the excess material and facilitate conforming the article to dimensional tolerances, e.g., for fitting the article to another component. The excess material may reduce a likelihood that the CMC (e.g., reinforcement material in the CMC) is damaged by the machining.

A method and apparatus to treat a dried unfired article comprising a ceramic precursor composition substantially held together by a binder, to be resistant to binder soluble solvent based processing. The method includes depositing a fluid on the article surface, and polymerizing the deposited fluid to form a polymer thin layer on the surface. The fluid may be an aerosol, a vapor, a fog, a mist, a smoke, or combinations thereof. An apparatus to perform the method and an article resistant to binder soluble solvent based processing are also provided. The article can be an unfired honeycomb body that includes a dried composition of ceramic precursor substantially held together by a binder and a layer disposed on a surface of the unfired honeycomb body. The surface to be exposed in the green state to a binder soluble solvent and the layer protects the binder from solubilization by the solvent.

A method and apparatus to treat a dried unfired article comprising a ceramic precursor composition substantially held together by a binder, to be resistant to binder soluble solvent based processing. The method includes depositing a fluid on the article surface, and polymerizing the deposited fluid to form a polymer thin layer on the surface. The fluid may be an aerosol, a vapor, a fog, a mist, a smoke, or combinations thereof. An apparatus to perform the method and an article resistant to binder soluble solvent based processing are also provided. The article can be an unfired honeycomb body that includes a dried composition of ceramic precursor substantially held together by a binder and a layer disposed on a surface of the unfired honeycomb body. The surface to be exposed in the green state to a binder soluble solvent and the layer protects the binder from solubilization by the solvent.