摘要:
A carbon material having oxidation resistance is prepared by forming a fi coating constituted mainly by carbon on the surface of a carbon/carbon composite by chemical vapor deposition, then forming on said first coating a second coating of a ceramic or both a ceramic and carbon by chemical vapor deposition, and changing at least one of thermal physical properties or mechanical physical properties of carbon in said first coating continuously or step-wise.
摘要:
A carbon/carbon composite having oxidation resistance is produced by filling the voids of a carbon/carbon composite comprising 10-70% by volume of carbon fibers and 5-90% by volume of a carbonaceous matrix and having a void percentage of 10-55%, with at least one of carbon and a ceramic by chemical vapor infiltration and then coating the deposit surface with a ceramic or both ceramic and carbon by chemical vapor deposition.
摘要:
The present invention relates to a method of producing a functionally grant material whose components and structure are continuously adjusted by the coating, plating and powder metallurgy techniques to change its function in turn and provide a method of producing a functionally gradient material superior in heat-resistance, corrosion-resistance and resistance to thermal fatigue by distributing a third component having a lower Young's modulus or formed of high-strength material sufficiently durable to the fracture strength among ceramics as a first component and metals or other ceramics as a second component to change the function.
摘要:
A crystalline sialon comprising crystals containing aluminum, silicon, nitrogen and oxygen, in which the crystal structure has a hexagonal system wurtzite structure identical with that of AlN crystals, and the volume of the unit cell thereof has a value smaller than that of the AlN crystals. The crystalline sialon can be synthesized by mixing a silicon-containing gas, an aluminum halide, a nitrogen atom-containing gas and an oxygen atom-containing gas, converting the gas mixture into plasmas by microwave discharging and depositing a film on the surface of a substrate, in which the temperature of the substrate, while controlling a flow rate of the silicon-containing gas and a flow rate of the oxygen-containing gas. The crystalline sialon of the present invention has high hardness, is excellent in oxidation resistance, as well as excellent in heat conductivity and adhesion with a superhard substrate.
摘要:
A manufacturing method of a forming die includes the steps of depositing a film of aluminum nitride or aluminum oxynitride on the forming surface of a forming member by passing an electric discharge through a mixture gas of halide of aluminum and a gas containing nitrogen atoms and hydrogen atoms or a mixture gas of halide of aluminum, a gas containing nitrogen atoms and a gas containing oxygen atoms by the application of a microwave and thereby ionizing the mixture gas, and fixing such a forming member on a die.
摘要:
A method of synthesizing metal-containing material by a plasma chemical vapor deposition comprises converting a reactive gas containing metal atoms into plasmas in a reaction chamber and supplying an inert gas from outside the plasma region in the reaction chamber. Ceramic films of excellent quality can be synthesized under stable conditions in an industrial mass production process.
摘要:
A method for advantageously producing sintered eutectic ceramics having a homogenous and dense structure, in particular, a eutectic containing a rare earth aluminate compound. The method allows eutectic powder of alumina and a rare earth aluminate compound to stand at a temperature of 1300-1700° C. for 1-120 minutes under vacuum or in an non-oxidative atmosphere under a pressure of 5-100 MPa using a spark plasma sintering apparatus, thereby causing crystal growth to occur to obtain a rare earth aluminate eutectic structure crystal.
摘要:
A drawing device 4 is mounted in a drawing shaft 3, and pipe replacement device A connected with new pipes is arranged on the side of starting shaft 2, wherein the drawing device 4 and the pipe replacement device A is connected through pull-rods 5 inserted into existing pipes with each other. The pipe replacement device A is comprised of a cutting part 11 including cutter bodies 14 (shanks 14a to 14i) arranged in the axial direction and at angular intervals in the circumferential direction, an expanding part 12 having expanding rollers 18a to 18f, and a connecting part 13. Each cutter body 14 has a plurality of cutting edges, wherein distances between the respective cutting edges and the center of the circle become larger in order from the forward side toward the backward side. While the pipe replacement device A is traveled in the inside of cast iron pipes, the inner wall of cast iron pipes is cut by the cutter bodies 14 to form grooves. Splitting of existing pipes into arc-shaped pieces 1a is made starting from the grooves. Arc-shaped pieces 1a are pressed into the ground, by which a tunnel 7 surrounded by arc-shaped pieces 1a and portions of consolidated earth is formed, while new pipes 6 are introduced into the tunnel 7, and besides the new pipes 6 are protected by protective armors formed of arc-shaped pieces 1a.
摘要:
A zirconia film formed on a substrate and having substantially one or two kinds of particular planes such as (200), (111) or (111) planes only oriented in parallel to the surface of the substrate, and a process for preparing it. This zirconia film is dense, and improved in the thermal resistance, thermal insulation properties and corrosion resistance.
摘要:
A super hard-highly pure silicon nitride includes a preferentially oriented crystalline silicon nitride having a grain size of 1-50 .mu.m and a micro Vickers hardness of 3,000 kg/mm.sup.2 under a load of 100 g, a finely grained crystalline silicon nitride having an average grain size of less than 1 .mu.m and a micro Vickers hardness of 3,500 kg/mm.sup.2 under a load of 100 g, and an amorphous silicon nitride having a micro Vickers hardness of 2,200 kg/mm.sup.2 under a load of 100 g, and is produced by blowing a nitrogen depositing source and a silicon depositing source on a substrate heated at 500.degree.-1,900.degree. C. with a blowpipe composed of a pipe assembly wherein a first pipe for the nitrogen depositing source is surrounded with the second pipe for silicon depositing source and the distance from an opening end of the first pipe to the substrate is shorter than a distance from an opening end of the second pipe to the substrate.