A method can be used for producing a powdery precursor material for an optoelectronic component having a first phase of the following general composition (Ca.sub.1-a-b-c-d-eZn.sub.dMg.sub.eSr.sub.cBa.sub.bX.sub.a).sub.2Si.sub.5N.sub.8, wherein X is an activator that is selected from the group of the lanthanoids and wherein the following applies: 0<a<1 and 0≦b≦1 and 0≦c≦ and 0≦d≦1 and 0≦e≦1. The method includes producing a powdery mixture of starting materials. The starting materials comprise ions of the aforementioned composition. At least silicon nitride having a specific surface area greater than or equal to 9 m/g is selected as a starting material and wherein the silicon nitride comprises alpha silicon nitride or is amorphous. The method also includes heat-treating the mixture under a protective gas atmosphere.

A ceramic honeycomb structure having pluralities of flow paths partitioned by porous cell walls, (a) the cell walls having porosity of 50-63%; and (b) in a pore diameter distribution in the cell walls measured by mercury porosimetry, (i) pore diameters at cumulative pore volumes corresponding to particular percentages of the total pore volume being within specific ranges and having specific relationships; (ii) the difference between a logarithm of the pore diameter at a cumulative pore volume corresponding to 20% of the total pore volume and a logarithm of the pore diameter at 80% being 0.39 or less; and (iii) the volume of pores of more than 100 μm being 0.03 cm.sup.3/g or less.

A ceramic honeycomb structure having pluralities of flow paths partitioned by porous cell walls; (a) the cell walls having porosity of 50-60%; and (b) in a pore diameter distribution in the cell walls measured by mercury porosimetry, (i) pore diameters at cumulative pore volumes corresponding to particular percentages of the total pore volume being within specific ranges and having specific relationships; and (ii) the difference between a logarithm of the pore diameter at a cumulative pore volume corresponding to 20% of the total pore volume and a logarithm of the pore diameter at 80% being 0.39 or less, and its production method.

A method to form a displacement, the method including disposing a powder blend comprising a plurality of ground ceramic particles and a plurality of ground resin particles into a mold, densifying the powder blend while in the mold, heating the mold to form a first displacement, impregnating said first displacement with a polymer precursor compound to form a second displacement, and heating the second displacement to form a third displacement.

Disclosed herein are methods of forming a hydrous kaolin clay product. The method can include (i) refining coarse crude kaolin clay to form a refined, coarse kaolin clay, and/or refining a tertiary, fine crude kaolin clay to form a refined, fine, hydrous kaolin clay, (ii) centrifuging the refined, coarse kaolin clay; the refined, fine, hydrous kaolin clay, or a blend thereof to provide a hydrous kaolin stream, and (iii) refining the hydrous kaolin stream to form the hydrous kaolin clay product. The hydrous kaolin stream can be blended with a delaminated, coarse kaolin clay, prior to refining the hydrous kaolin stream. The hydrous kaolin clay product can have a total alkali content of 0.2% or less by weight of the hydrous kaolin clay product. Compositions including cordierite ceramics, industrial coatings, paints, adhesives, inks, and fillers comprising the hydrous kaolin clay product are also described herein.

Provided are metal oxide ceramic materials and intermediate materials thereof (e.g., nanozirconia gels, nanozirconia green bodies, pre-sintered ceramic bodies, zirconia dental ceramic materials, and dental articles). The nanozirconia gels are formable gels. Also provided are methods of making and using the metal oxide materials and intermediate materials. The nanozirconia gels can be made using, for example, osmotic processing. The nanozirconia gels can be used to make nanozirconia green bodies, pre-sintered ceramic bodies, zirconia dental ceramic materials, and dental article. The nanozirconia green bodies, pre-sintered ceramic bodies, zirconia dental ceramic materials, and dental articles have desirable properties (e.g., optical properties and mechanical properties).

A powdery composition based on silica for ceramic welding, in particular by projection, comprising from 10 to 90% of a phase of siliceous particles comprise at least 80% by weight of cristobalite and at most 15% by weight of tridymite, based on the total weight of the composition, from 90 to 10% by weight of conventional additives forming a binding phase, based on the total weight of the composition, said siliceous particles having a d.sub.50 comprised between 350 and 800 μm, preferably between 400 and 500 μm.

A rare earth aluminate sintered compact including rare earth aluminate phosphor crystalline phases and voids, wherein an absolute maximum length of 90% or more by number of rare earth aluminate phosphor crystalline phases is in a range from 0.4 μm to 1.3 μm, and an absolute maximum length of 90% or more by number of voids is in a range from 0.1 μm to 1.2 μm.

Methods for making printed articles from carbon powder are described. Three-dimensional binder jet printing is used to make a printed article from the carbon powder. Methods are also provided for the production of near net shaped carbonized printed articles and graphitized printed articles.

Provided in one embodiment is a method of making, comprising: applying a hydrodynamic cavitation process to a raw material comprising particles comprising a metal-containing material or a carbon containing material of a first size to produce a slurry having particles comprising the metal-containing material or the carbon-containing material of a second size, smaller than the first size; and tape casting the slurry to form a green tape. Apparatuses employed to apply the method and the exemplary compositions made in accordance with the method are also provided.