A method of forming a ceramic matrix composite (CMC) component having an engineered surface includes applying a surface slurry comprising first particulate solids in a liquid carrier to an outer surface of a ceramic fiber preform. The surface slurry is dried to remove the liquid carrier, and thus a surface slurry layer comprising the first particulate solids is formed on the outer surface. The surface slurry layer is polished to a predetermined thickness and/or surface finish. After polishing, a ceramic tape comprising second particulate solids is applied to the surface slurry layer, and pressure is applied to attach the ceramic tape to the surface slurry layer and to induce consolidation of the ceramic tape and the surface slurry layer. Thus, a multilayer surface region comprising the surface slurry layer and a ceramic tape layer is formed on the ceramic fiber preform. The ceramic fiber preform and the multilayer surface region are infiltrated with a molten material, and, upon cooling, a CMC component having an engineered surface is formed.

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 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 medical device and associated methods are disclosed. In one example, the medical device includes an electrosurgical forceps. In selected examples, one or more structural components of the electrosurgical forceps includes a sintered ceramic microstructure. In selected examples other medical devices, including a debrider and a lithotripter, include a sintered ceramic microstructure.

Systems and methods include a computer-implemented method can be used to make drilling tools from new wurtzite boron nitride (w-BN) superhard material. An ultra-high-pressure, high-temperature operation is performed on pure w-BN powder to synthesize w-BN and cubic boron nitride (c-BN) compact having a first size greater than particles of the pure w-BN powder. The ultra-high-pressure, high-temperature operation includes pressurizing the w-BN powder to a pressure of approximately 20 Gigapascal, heating the w-BN powder at a heating rate of 100° C./minute and cooling the w-BN powder at a cooling rate of 50° C./minute. The compact is cut to a second size smaller than the first size using laser cutting tools. The cut compact is bonded metallurgically, mechanically, or both metallurgically and mechanically onto a tool substrate to form the drilling tool.

[Problem]

A technique for imparting high translucency which is similar to an enamel of a natural tooth to a zirconia sintered body, has been required.

[Solution]

To provide a zirconia mill blank for dental cutting and machining, containing, an yttrium compound and an indium compound as stabilizers, wherein, an amount of the yttrium compound is within a range of 3.0 mol % to 6.0 mol % in terms of oxide, an amount of the indium compound is within a range of 0.2 mol % to 3.0 mol % in terms of oxide, and a total amount of the yttrium compound and the indium compound is within a range of 5.5 mol % to 7.0 mol % in terms of oxide.

Sintered product having a chemical analysis such that, in mass percentages: SiO.sub.2 content is greater than 0.2% and less than 2%, and CaO content is greater than 0.1% and less than 1.5%, and MgO content is less than 0.3%, and alumina and other elements being the complement at 100%, the content of other elements being less than 1.5%, having a relative density greater than 90%, comprising, for more than 90% of its volume, a stack of ceramic platelets (10) laid flat, all of said platelets having an average thickness less than 3 μm, more than 95% by number of said platelets each containing more than 95% by mass of alumina, having a width (l) greater than 81 mm.

A gas turbine engine component includes a gas turbine engine component body formed of a ceramic matrix composite material having at least one fastener integrally formed with the gas turbine engine component body as a single-piece structure. The gas turbine engine component body initially comprises a rigidized preform structure formed from a polymer based material. The at least one fastener connects the gas turbine engine component body to an engine support structure.

A moldable green-body composite includes milling silicon nitride powder with a solvent and adding a surface modifier to the milled slurry to modify a surface of the silicon nitride particles. A polysiloxane in a solvent and a binder are also added to create a green body slurry. The solvents may be polar or non-polar solvents. A sintering aid, such as yttria-alumina, may be added to the slurry as well. A reduced density silicon nitride ceramic is made from the moldable green-body composite by molding the moldable green-body composite in a mold and curing at a curing temperature to convert the moldable green-body composite to a converted composite. The converted composite can then be sintered to form a reduced density silicon nitride ceramic that has a smooth surface finish and requires no post machining or polishing. The reduced density silicon nitride ceramic may also have very good dielectric properties.

A manufacturing system includes a tape advancing through the manufacturing system and a station of the manufacturing system. The tape includes a first portion having grains of an inorganic material bound by an organic binder. The station of the manufacturing system receives the first portion of the tape and prepares the tape for sintering by chemically changing the organic binder and/or removing the organic binder from the first portion of the tape, leaving the grains of the inorganic material, to form a second portion of the tape and, at least in part, prepare the tape for sintering.