The invention relates to an item made of a material consisting of a plurality of ceramic phases, said material including: a majority ceramic phase comprising nitrides and/or carbonitrides of one or more element(s) selected from among Ti, Zr, Hf, V, Nb, and Ta, said majority ceramic phase being present in a percentage by weight comprised between 60 and 98%, at least one minority ceramic phase, with either one single minority ceramic phase formed of zirconium and/or aluminium silicide, or several minority ceramic phases formed respectively of carbides of one or more element(s) selected from among Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W and of zirconium oxides and/or aluminium oxides, said at least one minority ceramic phase being present in its entirety in a percentage by weight comprised between 2 and 40%.

The present invention also relates to the method for manufacturing this item.

A cubic boron nitride (cBN)-based composite including about 30-65 vol. % cBN, about 15-45 vol. % titanium (Ti)-containing binders, about 2-20 vol. % zirconium dioxide (ZrO.sub.2), about 3-15 vol. % cobalt-tungsten-borides (Co.sub.xW.sub.yB.sub.z), and about 2-15 vol. % aluminum oxide (Al.sub.2O.sub.3).

This invention provides resin formulations which may be used for 3D printing and pyrolyzing to produce a ceramic matrix composite. The resin formulations contain a solid-phase filler, to provide high thermal stability and mechanical strength (e.g., fracture toughness) in the final ceramic material. The invention provides direct, free-form 3D printing of a preceramic polymer loaded with a solid-phase filler, followed by converting the preceramic polymer to a 3D-printed ceramic matrix composite with potentially complex 3D shapes or in the form of large parts. Other variations provide active solid-phase functional additives as solid-phase fillers, to perform or enhance at least one chemical, physical, mechanical, or electrical function within the ceramic structure as it is being formed as well as in the final structure. Solid-phase functional additives actively improve the final ceramic structure through one or more changes actively induced by the additives during pyrolysis or other thermal treatment.

Disclosed are a high-entropy nitride ceramic fiber, and a preparation method and use thereof. The high-entropy ceramic fiber comprises Ti, Hf, Ta, Nb, and Mo; the high-entropy nitride ceramic fiber presents single crystal phase, and each of the elements are uniformly distributed at molecular level. The preparation method of the high-entropy ceramic fiber comprises: mixing a high-entropy ceramic precursor comprising the target metal elements, a spinning aid, and a solvent uniformly to prepare a precursor spinning solution, followed by working procedures of spinning, pyrolyzation, and nitriding to prepare the high-entropy nitride ceramic fiber. The high-entropy nitride ceramic fiber can be used in photocatalysis process of carbon dioxide to prepare methane.

In additive manufacturing operations, powders used in stereolithographic processes need to be precisely spread out in a uniform fashion at every pass of the stereolithographic process to ensure predictability in powder surface morphology. Typically, this is difficult to achieve with conventional powders because often these powders suffer from poor flowability, which may further deteriorate over time, and impairs the efficiency of the stereolithographic processes. The present disclosure describes additive manufacturing powders having improved physical characteristics such as flowability and tap density, which are less sensitive or insensitive to ambient humidity. For example, there is described a powder that includes spherical particles having a particle size distribution of less than 1000 micrometers and having a measurable flowability as determined in accordance with ASTM B213 at 75% relative humidity.

A separator element comprising a porous rigid single-piece substrate (2) presenting firstly, at its periphery, a perimeter wall (2.sub.1) that is continuous between an inlet (4) for the fluid medium for treatment at one end of the porous substrate and an outlet (5) for the retentate at the other end of the porous substrate, and secondly, internally, a surface covered by a separator layer (6) and defining an open structure made up of empty spaces (3) for passing a flow of the fluid medium for treatment. The empty spaces (3) are arranged in the porous substrate so as to create within the porous substrate a first flow network (R1) for the fluid medium for treatment, having at least two interconnected flow circuits (R1.sub.1, R1.sub.2) for the fluid medium between the inlet (4) and the outlet (5) of the porous substrate.

A separator element comprising a porous rigid single-piece substrate (2) presenting firstly, at its periphery, a perimeter wall (2.sub.1) that is continuous between an inlet (4) for the fluid medium for treatment at one end of the porous substrate and an outlet (5) for the retentate at the other end of the porous substrate, and secondly, internally, a surface covered by a separator layer (6) and defining an open structure made up of empty spaces (3) for passing a flow of the fluid medium for treatment. The empty spaces (3) are arranged in the porous substrate so as to create within the porous substrate a first flow network (R1) for the fluid medium for treatment, having at least two interconnected flow circuits (R1.sub.1, R1.sub.2) for the fluid medium between the inlet (4) and the outlet (5) of the porous substrate.

A sintered material has 3% by volume or more and 80% by volume or less of cubic boron nitride grains and a binder. The binder contains: one or more types selected from the group consisting of one or more compounds composed of one or more first elements selected from the group consisting of a group 4 element, a group 5 element, a group 6 element, Al and Si and one or more second elements selected from the group consisting of C, N, O and B, and a solid solution of these compounds; and one or more metallic elements selected from the group consisting of Li, Ca, Na, Sr, Ba and Be. The binder contains the one or more metallic elements of 0.001% by mass or more and 0.5% by mass or less in total, and oxygen of 0.1% by mass or more and 10.0% by mass or less.

This invention relates to three-dimensional printing. This invention in particularly relates to a method of fabricating a three-dimensional object using a support edifice and also using a mold material with structural additives. The support edifice is fabricated in the same crafting material as the final three-dimensional object in the same manner as the printing of the final three-dimensional object (mold and crafting in a layer by layer manner). This method enables the support edifice to also transform during post processing in the same manner as the final three-dimensional object, thus supporting the object until finished. The system for fabricating the object comprises a dual printhead comprising a first dispensing nozzle for depositing the filament material in a flowable fluid form and a second dispensing nozzle for depositing the crafting medium, which is in a paste form. The printhead can also include a heating system or a drying apparatus. The three-dimensional imaging process for making objects, preferably metal objects or ceramic objects, on a layer-by-layer basis under the control of a data processing system is disclosed. The printing of the three-dimensional object such as heavy objects or an object having different parts having a very thin gap or space. It is important to use different processing steps and/or material to print such three-dimensional objects. The present invention provides a solution by printing a support edifice comprising a special structural additive for the mold, and further the support edifice can be printed simultaneously while printing the mold and crafting-paste material on a layer-by-layer basis. The mold material is mixed with the structural additive. The structural additive is useful for prohibiting either fusing of the object with the support edifice, or in alternative embodiments, the fusing of one part of an object with another part of an object.

A dielectric thin film contains Ca, Sr, Ti, Hf, O and N, wherein among crystal grains existing in a plane field of view of 1 μm square perpendicular to a film thickness direction of the dielectric thin film, a number ratio of crystal grains having a grain size of 19 nm or more and less than 140 nm is 95% or more, among the crystal grains existing in the plane field of view, a number ratio of first crystal grains having a grain size of 65 nm or more and less than 77 nm is 20% or more, and among the crystal grains existing in the plane field of view, a number ratio of second crystal grains having a grain size of 19 nm or more and less than 54 nm is 40% or less.