Abstract: 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.

Abstract: In order to provide a rare earth oxide-alumina type sintered body having no defect such as void and pore, and high strength, toughness and reliability, silica is added to a mixture of rare earth oxide and alumina to control a crystal grain size of the sintered body to not more than 30 .mu.m, whereby abnormal grain growth and occurrence of pore are restrained to produce a practically usable rare earth oxide-alumina-silica sintered body having excellent strength and toughness and uniform structure. According to this production method, rare earth oxide-alumina-silica sintered bodies having no defect such as void and pore, and high strength, toughness and reliability can easily be obtained.

Abstract: An electric discharge machine designed to prevent an impactive high-speed motion generated upon actuation of an electrode actuator from propagating to a quill, as well as to enable the rapid retreat of a tool electrode by the electrode actuator to be performed efficiently. The tool electrode is attached to a quill through an elastic supporting element and a piezoelectric actuator, with the elastic supporting element disposed on the side of the quill. The elastic supporting element has an elasticity whose degree is set so as not to adversely affect normal positioning of the tool electrode, and the piezoelectric actuator facilitates rapid retreat of the tool electrode. A support body includes a counter weight having a weight large enough to absorb the component of the impactive high-speed motion of the electrode actuator which acts toward the quill.

Abstract: A scroll type compressor having a pair of scroll type compression units which are encased in the same casing so as to make a common use of a lubricating oil reservoir provided in the casing, wherein the compression units have compression elements, drive shafts, driving motors and other components which are of the same constructions and specifications, and wherein each of the compression units are adapted to be driven selectively by commercial electrical power or through a frequency-variable inverter so as to operate at different speeds. Since both compression units can be made up from the same components such as the compression elements, loads in the production, service and administration, are greatly reduced contributing to a reduction in the labor and cost, while eliminating any mounting error.

Abstract: A wire cut electric discharge machine provided with a machining fluid supply apparatus capable of supplying machining fluid in an amount large enough to permit a stable wire extension even in a finishing operation. During rough machining, a first flow regulating valve (6) provided in a first pipe (3) and a second flow regulating valve (10) and an on-off valve (11) respectively provided in a second pipe (4) are fully opened, so that machining fluid is injected from upper and lower nozzles (5, 9) respectively connected to these pipes. In the finishing operation, openings of the first and second flow regulating valves are reduced.

Abstract: An Si.sub.3 N.sub.4 -Al.sub.2 O.sub.3 composite sintered body suitable for use in high-temperature structural materials consists of .alpha.-Al.sub.2 O.sub.3 and at least one crystal phase of Si.sub.3 N.sub.4 and sialon and is produced by sintering a shaped body of a particular Si.sub.3 N.sub.4 -Al.sub.2 O.sub.3 mixed powder at 1,500.degree.-1,900.degree. C.

Abstract: 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.

Abstract: A chemical vapor deposition method is disclosed for forming a dense and transparent or semitransparent zirconia film on a substrate which has 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method of manufacturing Josephson junctions includes steps of high Tc superconductor thin films on a substrates by chemical vapor deposition using raw materials, which includes at least yttrium, barium and copper, serving as vapor generating sources, and fabricating the high Tc superconductor thin films into micro-bridges to produce Josephson junctions.

Abstract: A membrane for use in an X-ray mask composed of a compound comprising at least three kinds of elements of boron (B), silicon (Si) and nitrogen (N) in which the content of silicon in the compound is at least 15 atomic percent, but less than 100 atomic percent, and the atomic ratio of Si/(B+Si) in the compound is at least 0.2, but less than one. The membrane is synthesized from source gases including at least the foregoing three kinds of elements by chemical reaction under such conditions that the ratio of nitrogen to boron plus silicon is at least one in the source gases and thereby depositing a film of the compound onto a substrate. Since the membrane thus prepared has a high transmittance in the visible region and X-ray and their residual stress can be readily controlled by adjusting the conditions for the formation of the membrane, it is suitable for the preparation of X-ray masks.

Abstract: 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.

Abstract: The specification discloses a polycrystalline boron nitride of high purity and high density consisting essentially of rhombohedral crystals in which the three-fold rotation axes, parallel to the c-axis in the notation of hexagonal crystal system, of the crystals have a preferred orientation. The polycrystalline rhombohedral boron nitride can be obtained as bulk or thin film articles with desired shapes by chemical vapor deposition including the steps of introducing a source gas of boron and a source gas into a reactor containing a heated substrate and depositing boron nitride onto the heated substrate, wherein a diffusion layer of the source gas of nitrogen and/or the carrier gas is formed around the substrate. The polycrystalline rhombohedral boron nitride such obtained is very useful in applications such as crucibles for melting semiconductors, various jigs for high temperature services, high-frequency insulator, microwave transmission window and source material of boron for semiconductor.

Abstract: A transparent BN-type ceramic material comprising 10 to 40 wt. % of boron (B), 35 to 55 wt. % of nitrogen (N) and 3 to 40 wt. % of silicon (Si) as the main component elements, and 1 to 10 wt. % of sub-component elements, with the property of not being crystallized by heat treatment at 1600.degree. C. for one hour, and a method of producing the above ceramic material by reacting a boron-containing compound, a nitrogen-containing compound and a silicon-containing compound at deposition temperatures in a range of more than 1300.degree. C. to less than 1700.degree. C. with the total gas pressure within a reaction furnace maintained in the range from 10 Torr to 100 Torr by use of a chemical vapor deposition method are disclosed.

Abstract: 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.

Abstract: An alumina-zirconia-silicon carbide sintered ceramic composite having high strength and high hardness is composed of 5 to 50 volume percent of partially stabilized zirconia powder of mean particle size between 0.1 and 1.0 .mu.m, 3 to 40 volume percent of silicon carbide powder of mean particle size smaller than 1 .mu.m or silicon carbide whiskers of 1 .mu.m or less in diameter with an aspect ratio between 3 and 200 or combination of said silicon carbide powder and said silicon carbide whiskers, the balance being substantially alumina powder, wherein zirconia plus silicon carbide accounts for 55 volume percent at most of the total.The sintered ceramic composite is manufactured by making a mixed powder composed of 5 to 50 volume percent of partially stabilized zirconia powder of mean particle size between 0.1 and 1.0 .mu.m, 3 to 40 volume percent of silicon carbide powder of mean particle size smaller than 1 .mu.m or silicon carbide whiskers of 1 .mu.

Abstract: Electrically conductive Si.sub.3 N.sub.4 --C series amorphous material having excellent thermal and mechanical characteristics is produced in a massive size by chemical vapor deposition.

Abstract: Boron nitride containing titanium nitride in an amount of 0.05 to 10 wt. % which is produced at a relatively low temperature, utilizing a chemical vapor deposition technique. In the deposition process, boron, titanium and nitrogen source gases are introduced into an evacuated reactor together with a carrier and/or diluent gas and contacted with a heated substrate previously mounted in the reactor, whereby boron nitride with titanium nitride is deposited onto the substrate. The deposit thus obtained has a high density, a significantly improved heat-shielding ability, a high degree of anisotropy with respect to thermal diffusivity and a high chemical stability. By using such anisotropic boron nitride with BN ceramics, very useful BN type composite ceramics can be produced.