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.

A sintered material includes a first phase and a second phase, wherein the first phase is composed of cubic boron nitride particles, and the following relational expressions are satisfied when more than or equal to two cubic boron nitride particles adjacent to and in direct contact with each other among the cubic boron nitride particles are defined as a contact body, Di represents a length of an entire perimeter of the contact body, n represents the number of contact locations at which the cubic boron nitride particles are in direct contact with each other, d.sub.k represents a length of each of the contact locations, and Σd.sub.k (where k=1 to n) represents a total length of the contact locations: Dii=Di+(2×Σd.sub.k (where k=1 to n)); and [(Dii−Di)/Dii]×100≤50.

A cubic boron nitride sintered material includes: 20 to 80 volume % of cBN grains; and 20 to 80 volume % of a binder phase, wherein the binder phase includes first binder grains and second binder grains, in each of the first binder grains, a ratio of the number of atoms of the first metal element to a total of the number of atoms of the titanium and the first metal element is more than or equal to 0.01% and less than 10%, in each of the second binder grains, the ratio is more than or equal to 10% and less than or equal to 80%, and an average grain size of the second binder grains is more than or equal to 0.2 μm and less than or equal to 1 μm.

A cubic boron nitride sintered material includes: 20 to 80 volume % of cBN grains; and 20 to 80 volume % of a binder phase, wherein the binder phase includes first binder grains and second binder grains, in each of the first binder grains, a ratio of the number of atoms of the first metal element to a total of the number of atoms of the titanium and the number of atoms of the first metal element is more than or equal to 0.01% and less than 10%, in each of the second binder grains, this ratio is more than or equal to 10% and less than or equal to 80%, and in an X-ray diffraction spectrum of the cubic boron nitride sintered material, one or both of conditions 1 and 2 are satisfied.

The present disclosure discloses a hybrid woven fiber preform-reinforced composite material, including a fiber preform, a composite material interface and a matrix, where the fiber preform is a three-dimensional fabric hybrid woven by 2-5 high-performance inorganic fibers, and the matrix is selected from the group consisting of resin, light alloy, carbon and ceramic. A preparation method of the composite material includes: preparing ceramic slurry, fiber bundle impregnation treatment, fiber weaving, molding of three-dimensional overall structure preform, preform heat treatment, preparing interface and preparing matrix. The present disclosure improves the weaving performance of inorganic rigid fibers, and the prepared hybrid woven fiber preform-reinforced composite material has desirable integrity, high interlayer bonding strength, and is not easy to layer. Meanwhile, the present disclosure realizes the functions of wave transmission, wave-absorbing, high-temperature structural material, thermal insulation and thermal prevention through the combination of hybrid woven fibers.

The present disclosure discloses a continuous electrophoretic deposition modified carbon fiber reinforced multi-matrix composite and a preparation method thereof, composing of a carbon fiber with a volume fraction of 30-55%, an inorganic powder with a volume fraction of 3-25% and a matrix with a volume fraction of 20-67%, wherein the inorganic powder is wrapped on the surface of the carbon fiber filament or embedded in the carbon fiber bundle, and the concentration gradually decreases from the fiber filament to the surface of the fiber bundle. The preparation method of the composite is as follows: (1) pretreating the carbon fibers; (2) preparing a slurry of the inorganic powder; (3) widening the pretreated carbon fiber to form a carbon fiber strip, and then carrying out electrophoretic deposition on the inorganic powders; (4) preparing a preform from the deposited carbon fibers; and (5) compounding a matrix in the preform.

Hafnium carbide powder for plasma electrodes is represented by a chemical formula HfC.sub.x (where x=0.5 to 1.0). The content of carbon particles contained as impurities in the hafnium carbide powder is less than or equal to 0.03% by mass. The hafnium carbide powder preferably has an average particle size of 0.5 to 2 μm. To produce the hafnium carbide powder, a pellet made from mixed powder of hafnium oxide and carbon is first placed in a second crucible made of silicon carbide. Then, the hafnium carbide powder is formed by heating the second crucible at 1800 to 2000° C. with the second crucible arranged in a first crucible made of carbon.

A sputtering target containing silicon nitride (Si.sub.3N.sub.4) with reduced specific resistance of is provided. A sputtering target including Si.sub.3N.sub.4, SiC, MgO and TiCN, wherein a specific resistance of the sputtering target is 10 mΩ.Math.cm or less.

Particles of a refractory metal or a refractory-metal compound capable of decomposing or reacting into refractory-metal nanoparticles, elemental silicon, and an organic compound having a char yield of at least 60% by weight are combined to form a precursor mixture. The mixture is heating, forming a thermoset and/or metal nanoparticles. Further heating form a composition having nanoparticles of a refractory-metal silicide and a carbonaceous matrix. The composition is not in the form of a powder

A cutting tool includes a base material, and a coating film covering the base material in contact with the base material. The base material is a cubic boron nitride sintered material. The coating film is a ceramic. An amount of oxygen in the coating film is less than or equal to 0.040 mass percent.