Patent classifications
C04B2235/465
Process for producing a silicon carbide-containing body
The present invention relates to a process for producing a silicon carbide-containing body (100), characterized in that the process has the following process steps: a) providing a mixture (16) comprising a silicon source and a carbon source, the silicon source and the carbon source being present together in particles of a solid granular material; b) arranging a layer of the mixture (16) provided in process step a) on a carrier (12), the layer of the mixture (16) having a predefined thickness; and c) treating the mixture (16) arranged in process step b) over a locally limited area with a temperature within a range from 1400 C. to 2000 C. according to a predetermined three-dimensional pattern, the predetermined three-dimensional pattern being selected on the basis of the three-dimensional configuration of the body (100) to be produced. Such a process allows simple and inexpensive production even of complex structures from silicon carbide.
Transformation enabled nitride magnets absent rare earths and a process of making the same
A process for producing an ordered martensitic iron nitride powder that is suitable for use as a permanent magnetic material is provided. The process includes fabricating an iron alloy powder having a desired composition and uniformity; nitriding the iron alloy powder by contacting the material with a nitrogen source in a fluidized bed reactor to produce a nitride iron powder; transforming the nitride iron powder to a disordered martensitic phase; annealing the disordered martensitic phase to an ordered martensitic phase; and separating the ordered martensitic phase from the iron nitride powder to yield an ordered martensitic iron nitride powder.
TITANIUM NITRIDE-REINFORCED ZIRCONIA TOUGHENED ALUMINA CERAMIC POWDER AND PREPARATION METHOD THEREOF
The present invention provides titanium nitride-reinforced zirconia toughened alumina (ZTA) ceramic powder and a preparation method thereof, and belongs to the technical field of ceramic materials. The preparation method provided in the present invention includes the following steps: mixing an aluminum salt, a zirconium salt, a yttrium salt, and a titanium salt with water to obtain a mixed aqueous solution, where the aluminum salt, the zirconium salt, the yttrium salt, and the titanium salt are water-soluble inorganic salts; mixing the obtained mixed aqueous solution and an alkaline precipitant for precipitation, to obtain hydroxide precipitate powder; successively conducting first calcination and second calcination on the obtained hydroxide precipitate powder, to obtain oxide solid solution powder; and subjecting the obtained oxide solid solution powder to selective nitridation reaction, to obtain titanium nitride-reinforced ZTA ceramic powder.
Al2O3-ZrO2-Y2O3-TiN Nancomposite Ceramic Powder And Preparation Method Thereof
The present invention provides an Al.sub.2O.sub.3ZrO.sub.2Y.sub.2O.sub.3TiN nanocomposite ceramic powder and a preparation method thereof, and belongs to the field of ceramic materials. In the ceramic powder provided by the present invention, a molar ratio of Zr:Al:Y:Ti is (3070):(1030):(0.41):(520). The nanocomposite ceramic powder provided by the present invention is good in dispersibility, and does not generate agglomeration, and the mechanical properties of a ceramic material obtained after sintering of the nanocomposite ceramic powder provided by the present invention are better. Proved by results of embodiments, the hardness of a ceramic material obtained by sintering of the nanocomposite ceramic powder provided by the present invention is 2835 GPa, and abrasion ratio is 45006000:1.
Method of forming a moisture-tolerant coating on a silicon carbide fiber
A method of forming a moisture-tolerant coating on a silicon carbide fiber includes exposing a silicon carbide fiber to a gaseous N precursor comprising nitrogen at an elevated temperature, thereby introducing nitrogen into a surface region of the silicon carbide fiber, and exposing the silicon carbide fiber to a gaseous B precursor comprising boron at an elevated temperature, thereby introducing boron into the surface region of the silicon carbide fiber. Silicon-doped boron nitride is formed at the surface region of the silicon carbide fiber without exposing the silicon carbide fiber to a gaseous Si precursor comprising Si. Thus, a moisture-tolerant coating comprising the silicon-doped boron nitride is grown in-situ on the silicon carbide fiber.
Method of fabricating a ceramic from a chemical reaction
A method of fabricating a ceramic material, the method including forming a ceramic material by performing a first chemical reaction at least between a first powder of an intermetallic compound and a reactive gas phase, a liquid phase being present around the grains of the first powder during the first chemical reaction, the liquid gas phase being obtained from a second powder of a metallic compound by melting the second powder or as a result of a second chemical reaction between at least one element of the first powder and at least one metallic element of the second powder, a working temperature being imposed during the formation of the ceramic material, which temperature is low enough to avoid melting the first powder.
BORON NITRIDE NANOTUBE (BNNT)-NANOPARTICLE COMPOSITES, METHODS FOR THE PREPARATION THEREOF AND THEIR MACROSCOPIC ASSEMBLIES
The present application relates to boron nitride nanotube (BNNT)-nanoparticle composites, to methods of preparing such composites and their use, for example, in metal/ceramic matrix composites and/or macroscopic assemblies. For example, the methods comprise subjecting a source of hydrogen, a source of boron, a source of nitrogen and a nanoparticle precursor to a stable induction thermal plasma and cooling the reaction mixture to obtain the composite.
METHOD FOR MANUFACTURING MULTILAYER ELECTRONIC COMPONENT
A method for manufacturing a multilayer electronic component having an element body in which a functional part and a conductor part are laminated. The green multilayer body 11 is formed on the temporary holding film 62 formed on the release substrate. The green multilayer body 11 is formed by repeating the first step forming a green functional part using the first ink containing the functional particles and the second step forming the green conductor part using the second ink containing the conductive particles. The temporary holding film 62 has conductivity.
Manufacturing of a ceramic article from a metal preform or metal matrix composite preform provided by 3D-printing or 3D-weaving
The present invention relates to a method of manufacturing a ceramic article (3) from a metal or metal matrix composite preform (1) provided by 3D-printing or by 3D-weaving. The preform (1) is placed in a heating chamber (2), and a predetermined time-temperature profile is applied in order to controllably react the preform (1) with a gas introduced into the heating chamber (2). The metal, the gas and the time-temperature profile are chosen so as to induce a metal-gas reaction resulting in at least a part of the preform (1) transforming into a ceramic. Preferred embodiments of the invention comprises a first oxidation stage involving a metal-gas reaction in order to form a supporting oxide layer (5) at the surface of the metal, followed by a second stage in which the heating chamber (2) is heated to a temperature above the melting point of the metal to increase the kinetics of the chemical reaction. The invention also relates to a number of advantageous uses of a ceramic article manufactured as described.
GALLIUM NITRIDE SINTERED BODY OR GALLIUM NITRIDE MOLDED ARTICLE, AND METHOD FOR PRODUCING SAME
The present invention provides a gallium nitride sintered body and a gallium nitride molded article which have high density and low oxygen content without using a special apparatus. According to the first embodiment, a gallium nitride sintered body, which is characterized by having density of 2.5 g/cm.sup.3 to less than 5.0 g/cm.sup.3 and an intensity ratio of the gallium oxide peak of the (002) plane to the gallium nitride peak of the (002) plane of less than 3%, which is determined by X-ray diffraction analysis, can be obtained. According to the second embodiment, a metal gallium-impregnated gallium nitride molded article, which is characterized by comprising a gallium nitride phase and a metal gallium phase that exist as separate phases and having a molar ratio, Ga/(Ga+N), of 55% to 80%, can be obtained.