Thermally-conductive ceramic and ceramic composite components suitable for high temperature applications, systems having such components, and methods of manufacturing such components. The thermally-conductive components are formed by a displacive compensation of porosity (DCP) process and are suitable for use at operating temperatures above 600° C. without a significant reduction in thermal and mechanical properties.

A method for the manufacture of a three-dimensional object using a refractory matrix material is provided. The method includes the additive manufacture of a green body from a powder-based refractory matrix material followed by densification via chemical vapor infiltration (CVI). The refractory matrix material can be a refractory ceramic (e.g., silicon carbide, zirconium carbide, or graphite) or a refractory metal (e.g., molybdenum or tungsten). In one embodiment, the matrix material is deposited according to a binder-jet printing process to produce a green body having a complex geometry. The CVI process increases its density, provides a hermetic seal, and yields an object with mechanical integrity. The residual binder content dissociates and is removed from the green body prior to the start of the CVI process as temperatures increase in the CVI reactor. The CVI process selective deposits a fully dense coating on all internal and external surfaces of the finished object.

A composite material manufacturing method includes: laminating a first sheet (210) including a first slurry (214) and a third sheet (230) including a third slurry (234); and heating the first sheet (210) and the third sheet (230) that are laminated to a temperature of transforming to ceramics by pyrolysis to form an intermediate body (300). The manufacturing method further includes impregnating the intermediate body (300) with a slurry and heating at a temperature lower than a temperature of transforming to ceramics by pyrolysis.

A muffle for an optical fiber draw furnace. The muffle including an inner surface and an outer surface, the inner surface forming an inner cavity. A protective coating is disposed on the inner surface, the protective coating having a melting point of about 1850° C. or greater. Furthermore, an absolute difference between a coefficient of thermal expansion of the protective coating and a coefficient of thermal expansion of a material of the muffle is 2.0 ppm/° C. or less over a temperature range from 25° C. to 1000° C.

A method for the manufacture of a three-dimensional object using a refractory matrix material is provided. The method includes the additive manufacture of a green body from a powder-based refractory matrix material followed by densification via chemical vapor infiltration (CVI). The refractory matrix material can be a refractory ceramic (e.g., silicon carbide, zirconium carbide, or graphite) or a refractory metal (e.g., molybdenum or tungsten). In one embodiment, the matrix material is deposited according to a binder-jet printing process to produce a green body having a complex geometry. The CVI process increases its density, provides a hermetic seal, and yields an object with mechanical integrity. The residual binder content dissociates and is removed from the green body prior to the start of the CVI process as temperatures increase in the CVI reactor. The CVI process selective deposits a fully dense coating on all internal and external surfaces of the finished object.

The disclosure relates to cubic boron nitride inserts for machining iron-based workpieces, as well as related methods and apparatuses. The insert includes a cutting element containing cubic boron nitride (cBN) in an amount in a range of 50 wt. % to 95 wt. % based on the cutting element, and a binder containing at least one of (i) alumina (Al.sub.2O.sub.3) and a manganese material (e.g., an oxide such as MnO.sub.x) and (ii) zirconia (ZrO.sub.2). The insert can be used for various machining processes, for example turning or boring. Suitable workpieces include iron-based materials or ferrous alloys, for example a cast iron such as compacted graphite iron (CGI).

An ink, and products formed from the ink, formulated at least in part from ceramic particles. The ink is formulated so that it can be used in additive manufacturing processes to form three-dimensional printed bodies. The three-dimensional printed bodies can have graded density and can be infiltrated by an infiltration material.

Methods of forming composite materials, composite materials, and articles. The composite materials may include electromagnetic shielding materials. The methods may include providing a mixture of ultra-high temperature ceramic particles and a liquid preceramic precursor, curing the mixture to form a solid mixture, forming particles of the solid mixture, and pressing the particles into a mold.

The present invention provides a silicon carbide fiber reinforced silicon carbide composite material, which is a composite material of SiC fibers and SiC ceramics with improved toughness and can be produced with high yield by relatively simple steps without complex steps such as a step of oxidation-resistant coating or an advanced interface control step. The silicon carbide composite material comprises a multiphase matrix and silicon carbide fibers disposed in the matrix, the matrix containing a silicon carbide phase and a phase that includes a substance of low reactivity with respect to silicon carbide. It can be obtained by steps suitable for mass production and ensures greatly improved fracture toughness while maintaining the excellent properties of SiC ceramics.

A polycrystalline diamond structure comprises a first region and a second region adjacent the first region, the second region being bonded to the first region by intergrowth of diamond grains. The first region comprises a plurality of alternating strata or layers, each or one or more strata or layers in the first region having a thickness in the range of around 5 to 300 microns. The polycrystalline diamond (PCD) structure has a diamond content of at most about 95 percent of the volume of the PCD material, a binder content of at least about 5 percent of the volume of the PCD material, and one or more of the layers or strata in the first region comprise and/or the second region comprises diamond grains having a mean diamond grain contiguity of greater than about 60 percent and a standard deviation of less than about 2.2 percent. There is also disclosed a method of making such a polycrystalline diamond structure.