A method of making a ceramic matrix composite that exhibits moisture and environmental resistance has been developed. The method includes depositing a diffusion barrier layer comprising boron nitride on silicon carbide fibers and depositing a moisture-tolerant layer comprising silicon-doped boron nitride on the diffusion barrier layer, where a thickness of the moisture-tolerant layer is from about 3 to about 300 times a thickness of the diffusion barrier layer. Thus, a compliant multilayer including the moisture-tolerant layer and the diffusion barrier layer is formed. A wetting layer comprising silicon carbide, boron carbide, and/or pyrolytic carbon is deposited on the compliant multilayer layer. After depositing the wetting layer, a fiber preform comprising the silicon carbide fibers is infiltrated with a slurry. After slurry infiltration, the fiber preform is infiltrated with a melt comprising silicon and then the melt is cooled, thereby forming a ceramic matrix composite.

The present invention provides a welding tool member for friction stir welding comprising a silicon nitride sintered body, wherein the silicon nitride sintered body includes an additive component other than silicon nitride in a content of 15% by mass or less, and the additive component includes three or more elements selected from Y, Al, Mg, Si, Ti, Hf, Mo and C. It is preferable that the content of the additive component is 3% by mass or more and 12.5% by mass or less. It is also preferable that the additive component includes four or more elements selected from Y, Al, Mg, Si, Ti, Hf, Mo and C. Due to above structure, there can be provided a welding tool member for friction stir welding having a high durability.

A method of forming a polycrystalline diamond comprises derivatizing a nanodiamond to form functional groups, and combining the derivatized nanodiamond with a microdiamond having an average particle size greater than that of the derivatized nanodiamond, and a metal solvent-catalyst. A polycrystalline diamond compact is prepared by adhering the polycrystalline diamond to a support, and an article such as a cutting tool may be prepared from the polycrystalline diamond compact.

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).

An abrasive article, comprising a polycrystalline material comprising abrasive grains and a filler material having an average negative coefficient of thermal expansion (CTE) within a range of temperatures between about 70 K to about 1500 K. A method of forming an abrasive article, comprising preparing an abrasive material, preparing a filler material having an average negative coefficient of thermal expansion (CTE) within a range of temperatures between about 150 K to about 1500 K, and forming a polycrystalline material comprising grains of the abrasive material and the filler material.

A light-emitting ceramic and a light-emitting device. The light-emitting ceramic comprises a YAG substrate and light-emitting centers and diffusion particles evenly dispersed in the YAG substrate. The light-emitting centers are lanthanide-doped YAG fluorescent powder particles of 10-20 μm in grain size. The particle size of the scattering particles is 20-50 nm. The YAG substrate is a lanthanide-doped YAG ceramic. Also, the grain size of the YAG substrate is less than the grain size of the YAG fluorescent powder particles.

A cubic boron nitride sintered body has between 50% and 75% cubic boron nitride by volume and between 25% and 50% binder phase by volume, and inevitable impurities. The binder phase contains an Al compound and a Zr compound. The Al compound contains Al and one or more of N, O and B; and the Zr compound contains Zr and one or more of C, N, O and B. At a polished surface of the cubic boron nitride sintered body, 40% or more of the Zr compounds satisfy the ratio 0.25≦n/N≦0.8, where: N represents the number of line segments drawn radially at equal intervals from a center of gravity of a given Zr compound to a boundary with a non-Zr compound; and n represents the number among those N line segments which intersect a boundary between the given Zr compound and cubic boron nitride.

A sintered body of the present invention is a sintered body including a first material and cubic boron nitride. The first material is partially-stabilized ZrO.sub.2 including 5 to 90 volume % of Al.sub.2O.sub.3 dispersed in crystal grain boundaries or crystal grains of partially-stabilized ZrO.sub.2.

Polycrystalline diamond compacts having parting compound within the interstitial volumes are disclosed herein. In one embodiment, a polycrystalline diamond compact includes a polycrystalline diamond body having a plurality of diamond grains bonded together in diamond-to-diamond bonds, interstitial volumes positioned between the adjacent diamond grains, and a parting compound positioned in at least a portion of the interstitial volumes of the polycrystalline diamond body.

This invention relates to a method for manufacturing a part of complex shape (3) by successive deposition of layers according to a technique of 3D additive printing and pressure sintering, comprising the following steps: an initial step of producing a model (1) from a material chosen from a porous or pulverulent material based on a metal alloy, a ceramic, a composite material and a lost material by formation of successive layers deposited according to the digitally controlled 3D additive printing technique, followed by a step of introducing a preform (1) made of porous or pulverulent material to be densified, derived from the model (1), into a mold (2) filled with a sacrificial porous or pulverulent material (13) in addition to the preform (1), the uniaxial densifying pressure sintering (10) then being applied to the mold (2) in order to form the part (3) which is finally extracted from the mold (2).