A film is formed by use of a composition containing (A) a binder resin, (B) a hard particle, and (C) a solid lubricant selected from the group containing molybdenum disulfide and graphite, wherein the composition contains tungsten carbide as the hard particle, and wherein weight ratio of (B) the hard particles and (C) the solid lubricant, (B)/(C), is in the range of 1 to 3.

A preceramic resin formulation comprising a polycarbosilane preceramic polymer, an organically modified silicon dioxide preceramic polymer, and, optionally, at least one filler. The preceramic resin formulation is formulated to exhibit a viscosity of from about 1,000 cP at about 25° C. to about 5,000 cP at a temperature of about 25° C. The at least one filler comprises first particles having an average mean diameter of less than about 1.0 μm and second particles having an average mean diameter of from about 1.5 μm to about 5 μm. Impregnated fibers comprising the preceramic resin formulation are also disclosed, as is a composite material comprising a reaction product of the polycarbosilane preceramic polymer, organically modified silicon dioxide preceramic polymer, and the at least one filler. Methods of forming a ceramic matrix composite are also disclosed.

The friction stir welding tool member according to the present invention is made of a silicon nitride sintered body, wherein the silicon nitride sintered body contains 15% by mass or less of additive components except silicon nitride in such a manner that the additive components include at least one element selected from lanthanoid elements and at least one element selected from Mg, Ti, Hf, and Mo. In addition, it is preferable that the additive components further include at least one element selected from Al, Si, and C. According to the above-described configuration, a friction stir welding tool member having an excellent durability can be provided.

A cubic boron nitride (cBN)-based composite including about 30-65 vol. % cBN, about 3-30 vol. % zirconium (Zr)-containing compounds, about 0-10 vol. % cobalt-tungsten-borides (Co.sub.xW.sub.yB.sub.z), about 2-30 vol. % aluminum oxide (Al.sub.2O.sub.3), about 0.5-10 vol. % tungsten borides, and less than or equal to about 5 vol. % aluminum nitride (AlN).

The present invention relates to preceramic polymer grafted nanoparticles and as well as methods of making and using same. Advantages of such preceramic polymer grafted nanoparticles include, reduced out gassing, desired morphology control and desirable, distinct rheological properties that are not found in simple mixtures. As a result, Applicants' preceramic polymer grafted nanoparticles can be used to provide significantly improved, items including but not limited to hypersonic vehicles, jets, rockets, mirrors, signal apertures, furnaces, glow plugs, brakes, and armor.

To achieve local melting of an inorganic material powder containing an inorganic material as a main component in an additive manufacturing technology, to thereby achieve high shaping accuracy. Provided is an inorganic material powder to be used in an additive manufacturing method involving performing shaping through irradiation with laser light, the inorganic material powder including: a base material that is an inorganic material; and an absorber, wherein the absorber has a higher light-absorbing ability than the base material for light having a wavelength included in the laser light, and contains any one of Ti.sub.2O.sub.3, TiO, SiO, ZnO, antimony-doped tin oxide (ATO), and indium-doped tin oxide (ITO), or contains any one of a transition metal carbide, a transition metal nitride, Si.sub.3N.sub.4, AlN, a boride, and a silicide.

A method for the preparation of a dense HfC(Si)—HfB.sub.2 composite ceramic. hafnium oxide powders, nano-sized carbon black and silicon hexaboride powders are mixed in a molar ratio of (1-10):(1-20):(1-5) to obtain a powder mixture. The powder mixture is subjected to ball milling, dried and transferred to a graphite mold for spark plasma sintering. In this way, an in-situ carbon-boron reduction reaction and the sintering densification are completed in one step, and the obtained HfC(Si)—HfB.sub.2 composite ceramic has a density of 94.0%-100% and uniformly dispersed grains.

The sliding member according to the embodiment includes a silicon nitride sintered body that includes silicon nitride crystal grains and a grain boundary phase, in which a percentage of a number of the silicon nitride crystal grains including dislocation defect portions inside the silicon nitride crystal grains among any 50 of the silicon nitride crystal grains having completely visible contours in a 50 μm×50 μm observation region of any cross section or surface of the silicon nitride sintered body is not less than 0% and not more than 10%. The percentage is more preferably not less than 0% and not more than 3%.

The present disclosure generally relates to silicon carbide crystals which may be used in optical applications, and to methods for producing the same. In one form, a composition includes an aluminum doped silicon carbide crystal having residual nitrogen and boron impurities. The concentration of aluminum in the silicon carbide crystal is greater than the combined concentrations of nitrogen and boron in the silicon carbide crystal, and the silicon carbide crystal includes an optical absorption coefficient of less than about 0.4 cm.sup.−1 at a wavelength in a range between about 400 nm to about 800 nm.

An optical device includes a vanadium compensated, high resistivity, SiC single crystal of 6H or 4H polytype, for transmitting light having a wavelength in a range of from 420 nm to 4.5 μm. The device may include a window, lens, prism, or waveguide. A system includes a source for generating light having a wavelength in a range of from 420 nm to 4.5 μm, and a device for receiving and transmitting the light, where the device includes a vanadium compensated, high resistivity, SiC single crystal of 6H or 4H polytype. The disclosure also relates to crystals and methods for optical applications, including an aluminum doped SiC crystal having residual nitrogen and boron impurities, where the aluminum concentration is greater than the combined concentrations of nitrogen and boron, and where an optical absorption coefficient is less than about 0.4 cm.sup.−1 at a wavelength between about 400 nm to about 800 nm.