摘要:
Process for preparing NbN superconducting material, characterized in that a bulk Nb is placed in powder including at least one metal which can be nitriding-burned, and then the powder is heated to be nitriding-burned in pressurized N.sub.2 atmosphere so that the bulk Nb is nitrided by the nitriding-burning of the powder.
摘要:
The present invention relates to a method of sintering ceramics and ceramics obtained by said method. According to the present invention, the synthesis and sintering of ceramics can be simultaneously carried out by utilizing the reaction heat generated when at least one metallic element selected from metallic elements of IIb, IVb, Vb and VIb groups of the Periodic Table is combined with at least one nonmetallic element such as B, C N and Si without heat or by preliminarily heating the ceramics at temperatures remarkably lower than the usual sintering temperature ceramics thus-produced are superior in abrasion resistance and corrosion resistance. Furthermore, according to the present invention, particles of the same kind of metal as that used in constructing the ceramics comprising the above described metallic elements and nonmetallic elements are dispersed in a matric comprising said ceramics to obtain metal dispersed reinforced ceramics in which both the matrix and the metallic particles are strongly and chemically bonded to each other. According to the latter procedure, ceramic materials having high temperature characteristics, high corrosion resistance and high abrasion resistance, as well as high toughness and high impact resistance can be obtained.
摘要:
The present invention relates to a method of sintering ceramics and ceramics obtained by said method. According to the present invention, the synthesis and sintering of ceramics can be simultaneously carried out by utilizing the reaction heat generated when at least one metallic element selected from metallic elements of IIIb, IVa, Vb and VIb groups of the Periodic Table is combined with at least one nonmetallic element such as B, C, N and Si without heat or by preliminarily heating the ceramics at temperatures remarkably lower than the usual sintering temperature ceramics, thus-produced are superior in abrasion resistance and corrosion resistance. Furthermore, according to the present invention, particles of the same kind of metal as that used in constructing the ceramics comprising the above described metallic elements and nonmetallic elements are dispersed in a matrix comprising said ceramics to obtain metal dispersed reinforced ceramics in which both the matrix and the metallic particles are strongly and chemically bonded to each other. According to the latter procedure ceramic materials having high temperature characteristics, high corrosion resistance and high abrasion resistance, as well as high toughness and high impact resistance can be obtained.
摘要:
A high strength Si.sub.3 N.sub.4 composite composed of a sintered body consisting mainly of Si.sub.3 N.sub.4 in which SiC whiskers with a small aspect ratio, preferably an average aspect ratio of 15 to 100, is contained in the sintered body and thereby a considerable improvements can be obtained in the mechanical properties, such as strength, toughness and mechanical shock resistance. The composite is produced by mixing the SiC whiskers with Si.sub.3 N.sub.4 powder and then sintering the resulting mixture by a hot isostatic pressing without using a sintering aid.
摘要翻译:烧结体中含有由主要由Si 3 N 4组成的烧结体构成的高强度Si 3 N 4复合体,其特征在于,在烧结体中含有长宽比小的SiC晶须,平均纵横比优选为15〜100,由此可以获得显着的改善 机械性能如强度,韧性和机械冲击强度。 通过将SiC晶须与Si 3 N 4粉末混合,然后通过热等静压法烧结所得混合物而不使用烧结助剂来制备复合材料。
摘要:
There is provided a three dimensional periodic structure comprising two substances having different dielectric constants with a high contrast between the dielectric constants or refractive indexes, periodically distributed in a three dimensional space. A unit cell substrate having air holes in a diamond structure is formed by a stereo lithography method which repeats the step of irradiating light onto a liquid surface of a light-hardening resin such as a photosensitive epoxy resin in each layer in a cross-sectional pattern to be formed. Then, a conductive film made of, for example, Cu is formed by an electroless plating method on the surface of the unit cell substrate. Thus, a three dimensional periodic structure comprising two substances having different dielectric constants, i.e., resin and air, periodically distributed in a three dimensional space, and comprising a conductive film formed at an interface between the two substances is obtained.
摘要:
Achieved is a ceramic carbon composite material and a ceramic-coated ceramic carbon composite material which are lighter than ceramics and excellent in at least one of properties including oxidation resistance, resistance to dust generation, heat conductivity, electrical conductivity, strength, and denseness. The ceramic carbon composite material is a ceramic carbon composite material in which an interfacial layer of a ceramic is formed between carbon particles of or containing graphite. The ceramic carbon composite material can be produced by forming a green body from ceramic-coated powder in which the surfaces of carbon particles of or containing graphite are coated with individual ceramic layers and sintering the green body.
摘要:
Photonic crystal units (10a, 10b, and 10c) are formed by an optical molding process using a photocurable resin, and partitions (11) are provided at the boundaries therebetween. The voids in each photonic crystal unit are filled with a second substance containing ceramic particles dispersed therein to form a filled portion 2. A plurality of three-dimensional periodic structure units containing the first and second substances distributed with three-dimensional periodicity are arranged so as to have different ratios between the dielectric constants of the first and second substances. Therefore, present invention provides a three-dimensional periodic structure having a wide photonic band gap which could not be obtained in a conventional three-dimensional periodic structure.
摘要:
A metallic base material is covered with a coating layer of intermetallic compound, or a plurality of metallic base materials are welded to each other with an intermetallic compound, with reduced energy consumption within a short period of time. First metallic substance 31 in powdery form is piled up on metallic base material 2. Second metallic substance 3 in molten form is delivered onto piling layer 80 of the first substance. Thus, under the control of reaction initiation temperature, coating layer (or building up coating layer) 84 of intermetallic compound having a thickness of hundreds of microns (&mgr;m) to millimeters (mm) is formed on the base material 2 by the self-exothermic reaction between the first substance and the second substance. This method is also useful in the welding of a plurality of metallic base materials to each other with an intermetallic compound. The first substance can be constituted of, for example, Ni, Co or Fe. The second substance can be constituted of, for example, Al or Ti. Each base material may be constituted of a metal common with or homologous to the first substance or second substance. The first substance and the second substance can be used in powdery form or molten form, provided that at least one thereof is used in molten form. The first substance may contain a ceramic for imparting reinforcement.
摘要:
A coated diamond which is dense and excellent in adherence and enables diamond to exhibit its superior characteristics, a manufacturing method and a composite material of the coated diamond are achieved. The coated diamond includes a diamond (1) and an SiC film (2) coating the diamond (1). The SiC mentioned above is substantially formed of &bgr;-SiC and a value of ratio I (220)/I (111) is at least 0.38 and at most 0.55, I (220) representing peak intensity of Miller index (220) of SiC and I (111) representing peak intensity of Miller index (111) thereof.
摘要:
A carbon material and a method of manufacturing the carbon material are provided that can improve hardness and physical properties while fully gaining the benefit of SPS method, which makes it possible to obtain a dense carbon material with very short time. The carbon material is manufactured by a first step of filling mixture powder containing a carbon aggregate and a binder in a mold, and a second step of sintering the mixture powder by a spark plasma sintering method while compressing the mixture powder. The carbon material is characterized by having a Shore hardness HSD value of 60 or greater, and having a thermal expansion anisotropy ratio, an electrical resistivity anisotropy ratio, or a thermal conductivity anisotropy ratio, of 1.5 or greater.