A cutting tool, including a silicon nitride (Si.sub.3N.sub.4) ceramic substrate, and a diamond film coated on the surface of the Si.sub.3N.sub.4 ceramic substrate. The diamond film has a thickness of 7-12 μm. The cutting tool includes a tool nose, a blade, and a handle. The blade has a rake angle γ of 5-15°, a clearance angle α of 10-14°, and a helix angle of 15-45°. The blade includes four cutting edges.

The localized formation of graphene and diamond like structures on the surface of boron carbide is obtained due to exposure to high intensity laser illumination. The graphitization involves water vapor interacting with the laser illuminated surface of boron carbide and leaving behind excess carbon. The process can be done on the micrometer scale, allowing for a wide range of electronic applications. Raman is a powerful and convenient technique to routinely characterize and distinguish the composition of Boron Carbide (B.sub.4C), particularly since a wide variation in C content is possible in B.sub.4C. Graphitization of 1-3 μm icosahedral B.sub.4C powder is observed at ambient conditions under illumination by a 473 nm (2.62 eV) laser during micro-Raman measurements. The graphitization, with ˜12 nm grain size, is dependent on the illumination intensity. The process is attributed to the oxidation of B.sub.4C to B.sub.2O.sub.3 by water vapor in air, and subsequent evaporation, leaving behind excess carbon. The effectiveness of this process sheds light on amorphization pathways of B.sub.4C, a critical component of resilient mechanical composites, and also enables a means to thermally produce graphitic contacts on single crystal B.sub.4C for nanoelectronics.

The localized formation of graphene and diamond like structures on the surface of boron carbide is obtained due to exposure to high intensity laser illumination. The graphitization involves water vapor interacting with the laser illuminated surface of boron carbide and leaving behind excess carbon. The process can be done on the micrometer scale, allowing for a wide range of electronic applications. Raman is a powerful and convenient technique to routinely characterize and distinguish the composition of Boron Carbide (B.sub.4C), particularly since a wide variation in C content is possible in B.sub.4C. Graphitization of 1-3 μm icosahedral B.sub.4C powder is observed at ambient conditions under illumination by a 473 nm (2.62 eV) laser during micro-Raman measurements. The graphitization, with ˜12 nm grain size, is dependent on the illumination intensity. The process is attributed to the oxidation of B.sub.4C to B.sub.2O.sub.3 by water vapor in air, and subsequent evaporation, leaving behind excess carbon. The effectiveness of this process sheds light on amorphization pathways of B.sub.4C, a critical component of resilient mechanical composites, and also enables a means to thermally produce graphitic contacts on single crystal B.sub.4C for nanoelectronics.

Disclosed are devices and methods for semiconductor devices including a ceramic substrate. Aspects disclosed include semiconductor device including an electrical component, an alumina ceramic substrate and a substrate-film. The substrate-film is deposited on the alumina ceramic substrate. The substrate-film has a planar substrate-film surface opposite the alumina ceramic substrate. The electrical component is formed on the substrate-film surface of the substrate-film on the alumina ceramic substrate.

Disclosed are devices and methods for semiconductor devices including a ceramic substrate. Aspects disclosed include semiconductor device including an electrical component, an alumina ceramic substrate and a substrate-film. The substrate-film is deposited on the alumina ceramic substrate. The substrate-film has a planar substrate-film surface opposite the alumina ceramic substrate. The electrical component is formed on the substrate-film surface of the substrate-film on the alumina ceramic substrate.

Ground surface comprising a substrate (110) having a Young's modulus of between 100 and 1000 GPa, and in which the ground surface has, on a working surface (120), a Vickers hardness of between 1300 and 10 000 kgf/mm.sup.2, and/or a surface coating forming the working surface, in which the surface coating contains amorphous carbon and/or titanium nitride and/or chromium nitride and/or tungsten carbide.

Techniques for infiltrating a CMC substrate may include infiltrating the CMC substrate with a first slurry to at least partially fill at least some inner spaces of the CMC substrate, where the first slurry includes first solid particles, drying the first slurry to form an infiltrated CMC including the first solid particles, depositing a second slurry including a carrier material and second solid particles on a surface of the infiltrated CMC, where the second solid particles include a plurality of fine ceramic particles, a plurality of coarse ceramic particles, and a plurality of diamond particles, drying the second slurry to form an article having an outer surface layer including the second solid particles on the infiltrated CMC, and infiltrating the article with a molten infiltrant to form a composite article.

Techniques for infiltrating a CMC substrate may include infiltrating the CMC substrate with a first slurry to at least partially fill at least some inner spaces of the CMC substrate, where the first slurry includes first solid particles, drying the first slurry to form an infiltrated CMC including the first solid particles, depositing a second slurry including a carrier material and second solid particles on a surface of the infiltrated CMC, where the second solid particles include a plurality of fine ceramic particles, a plurality of coarse ceramic particles, and a plurality of diamond particles, drying the second slurry to form an article having an outer surface layer including the second solid particles on the infiltrated CMC, and infiltrating the article with a molten infiltrant to form a composite article.

A superhard polycrystalline construction comprises a body of polycrystalline superhard material comprising a structure comprising superhard material, the structure having porosity greater than 20% by volume and up to around 80% by volume. A method of forming such a superhard polycrystalline construction comprises forming a skeleton structure of a first material having a plurality of voids, at least partially filling some or all of the voids with a second material to form a pre-sinter assembly, and treating the pre-sinter assembly to sinter together grains of superhard material to form a body of polycrystalline superhard material comprising a first region of superhard grains, and an interpenetrating second region; the second region being formed of the other of the first or second material that does not comprise the superhard grains; the superhard grains forming a sintered structure having a porosity greater than 20% by volume and up to around 80% by volume.

A seal assembly for a gas turbine engine having a seal formed of a carbon material; and a seal seat positioned for rotation relative to the seal, wherein the seal and the seal seat each have a sealing surface which together define a sliding seal, and further having a carbon film on the sealing surface of the seal seat.