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:
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.
摘要翻译:通过化学气相沉积以大规模生产具有优异的热和机械特性的导电Si 3 N 4 -C系列非晶材料。
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 5,000 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 a second pipe for the silicon depositing source and the distance from an opening end of the first pipe to the substrate is shorter than the distance from an opening end of the second pipe to the substrate.
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 a second pipe for the silicon depositing source and the distance from an opening end of the first pipe to the substrate is shorter than the distance from an opening end of the second pipe to the substrate.
摘要:
A sintering furnace for sintering an object to be sintered formed of ceramics, fine ceramic materials, etc. to produce a sintered object and a method therefor. An insulating wall (28) and an inner shell (25) define a sintering chamber (16) for sintering an object to be sintered (10). Thermal equilibrium is maintained between the inner shell (25) and the object to be sintered (10), and the object to be sintered (10) is completely pseudo-adiabatically isolated to achieve more uniform and small energy consuming sintering. The thickness of the insulating wall (28) increases gradually from an inlet (20) toward an outlet (21). The object to be sintered (10) is fed by a carriage provided in a sintering furnace from the inlet (20) to the outlet (21) in the sintering chamber (16). Thereby, a temperature distribution corresponding to a plurality of processes can be easily formed in one furnace to sinter continuously the object to be sintered (10) in the furnace.
摘要:
A method of producing multilayered optical filters by using a genetic algorithm that determines an optimal combination of refractive indexes and thicknesses for each layer of the filter is described. The method generates initial values for the component and places the values within a matrix P, where P=(X1, X2, X3, . . . , Xi, . . . , Xs) and Xi is an elementary matrix that includes the refractive index and thickness of each layer i. The method may generate mutated patterns by increasing or decreasing the thicknesses and refractive indexes of the initial pattern. It may also perform a cross-over process, selecting patterns from grouping of mutated patterns. Alternately, the method may perform a process where selected patterns having optical characteristics closest to the desired characteristics from the initial, mutated or crossover patters are chosen. The genetic algorithm utilizing the above processes repeats until the optical characteristics fall within the desired range.
摘要:
Described herein is an optical multilayered-film filter which provides less interference and a good optical characteristic and is high in productivity. The optical multilayered-film filter wherein dielectric thin films are stacked on each other in a multilayer form in a single direction, comprises a refractive-index inclined laminated portion in which refractive indices of dielectric thin-film layers are successively inclined and changed in a laminating direction, and an alternately-laminated portion in which a dielectric thin-film layer having a high refractive index and a dielectric thin-film layer having a low refractive index are alternately laminated on each other.
摘要:
In order to provide a mixed oxide ceramic sintered body having no defect such as void and pore, and high strength, toughness and reliability, a mixed oxide of rare earth oxide-alumina oxide added with silica is fired with a non-oxide mixture of SiC and/or Si.sub.3 N.sub.4. In the production method, the crystal grain size of the sintered body is controlled to not more than 30 .mu.m, and abnormal grain growth and occurrence of pore can be restrained to easily produce a practically usable mixed oxide ceramic sintered body having excellent toughness inherent to oxide sintered body and excellent high-temperature strength inherent to SiC and Si.sub.3 N.sub.4 and uniform structure.
摘要:
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.