摘要:
A circumferential coating material to be applied to a circumferential surface of a honeycomb structure made of ceramics formed by extrusion, the circumferential coating material including a ceramic raw material that forms a circumferential coating layer, wherein the ceramic raw material contains: a ceramic mixture of first ceramic particles having particulate shapes, and second ceramic particles having particulate shapes and an average particle diameter different from an average particle diameter of the first ceramic particles; and a fiber material having an elongated strip-like shape, wherein the ceramic mixture has particle size distribution including at least two local maximum values, and the fiber material has an average fiber length ranging from 30 to 100 μm in a longitudinal direction.
摘要:
A production process which comprises a preform formation step of forming a fiber preform made of silicon carbide short fibers having heat resistance of 1000° C. or greater; a sol-gel preparation step of preparing a sol-gel solution containing a heat resistant compound having heat resistance of 1000° C. or greater; an impregnation-drying-calcination step of impregnating the fiber preform with the sol-gel solution, followed by drying and calcining; and a crystallization step of crystallizing the fiber preform after impregnation, drying and calcination.
摘要:
A method of preparing a light weight concrete composition using expanded polymer particles that includes a) replacing from about 10 to about 50 volume percent of the coarse aggregate in the concrete composition with prepuff particles; and b) preparing the concrete composition by combining ingredients comprising 3-40 volume percent cement, 1-50 volume percent fine aggregate, 0-40 volume percent coarse aggregate, 10-22 volume percent water, and 5-40 volume percent of prepuff particles. The prepuff particles have an average particle diameter of from 0.2 mm to 5 mm, a bulk density of from 0.02 g/cc to 0.56 g/cc, an aspect ratio of from 1 to 3. The concrete composition has a density of from about 90 to about 135 lb./ft3 and after it is set for 28 days, has a compressive strength of at least 1800 psi as tested according to ASTM C39.
摘要:
A honeycomb structure includes at least one honeycomb unit a NOx occluding catalyst and a noble metal catalyst. The at least one honeycomb unit includes inorganic particles and an inorganic binder and has a plurality of cell walls extending from one end face to another end face of the at least one honeycomb unit along a longitudinal direction of the at least one honeycomb unit to define a plurality of cells. The NOx occluding catalyst and the noble metal catalyst are provided at the plurality of cell walls. An amount of the noble metal catalyst provided on a surface of at least one of the plurality of cell walls is greater than an amount of the noble metal catalyst provided in a center part along a thickness of the at least one of the plurality of cell walls.
摘要:
A honeycomb structure includes a first end face, a second end face, a honeycomb unit, and an ammonia adsorbing material. The second end face is located opposite to the first end face along a longitudinal direction of the honeycomb structure. The honeycomb unit has plural cell walls extending along the longitudinal direction from the first end face to the second end face to define plural cells. The cell walls include a NOx adsorbing material and an inorganic binder. The ammonia adsorbing material is supported on the cell walls. An amount of the ammonia adsorbing material supported on the cell walls is varied between the first end face and the second end face.
摘要:
A honeycomb structure includes a plurality of honeycomb fired bodies combined with one another. The honeycomb fired bodies include a center-portion honeycomb fired body located in a center portion in a cross section perpendicular to a longitudinal direction and a peripheral-portion honeycomb fired body located in a peripheral portion in the cross section. The center-portion honeycomb fired body has a substantially rectangular cross-sectional shape and has an area from about 2500 mm2 to about 5000 mm2 in the cross-section. A cross-sectional shape of the peripheral-portion honeycomb fired body is different from the cross-sectional shape of the center-portion honeycomb fired body. A cross-sectional area of the peripheral-portion honeycomb fired body perpendicular to the longitudinal direction is from about 0.9 times to about 1.3 times as large as the cross-sectional area of the center-portion honeycomb fired body.
摘要:
A lightweight concrete composition containing from 10 to 90 volume percent of a cement composition, from 10 to 90 volume percent of particles having an average particle diameter of from 0.2 mm to 8 mm, a bulk density of from 0.03 g/cc to 0.64 g/cc, an aspect ratio of from 1 to 3, and from 0 to 50 volume percent of aggregate, where the particles contain an antimicrobial agent; where the sum of components used does not exceed 100 volume percent, and where after the lightweight concrete composition is set it has a compressive strength of at least 1700 psi as tested according to ASTM C39 after seven days. The concrete composition can be used to make concrete masonry units, construction panels, dining tables, counter surfaces, bench tops, and/or examination tables as well as other articles.
摘要:
A modified alkali silicate composition for forming an inorganic polymer matrix having improved mechanical properties. The modified alkali silicate matrix is made by reacting an alkali silicate (or its precursors such as an alkali hydroxide, a SiO2 source and water), a non-silicate network former and/or reactive glass, water and optionally one or more multivalent cation(s) selected from Groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16 of the periodic table such as an alkaline earth salt, water and optional processing aids. An inorganic matrix composite can be prepared by applying a slurry of the modified aqueous alkali silicate composition to a reinforcing medium and curing the composite at a temperature from about 15° C. up to 1000° C. and a pressure of up to 20,000 psi for typical high-performance organic polymer processing (temperatures about 15° C. to about 200° C. and pressures
摘要:
A process for forming a uniform, boron nitride coating on a boron-doped, refractory carbide body, and in particular on a sintered, boron-doped, silicon carbide fiber, where the body is exposed to a nitrogen-containing atmosphere at a temperature equal to or greater than the densification or sintering temperature. The coated fibers exhibit no loss in strength properties and show improved creep resistance.
摘要:
The invention concerns a method for metal coating of fibres (15) by liquid process, said method being particularly but not exclusively designed for coating in thick and even layers (22) with metals and metal alloys having high melting point and reactivity. Said method is characterised in that it consists in moving along the stretched fibre (15) in the liquid metal maintained in levitation in a well (1), said fibre (15) passing through orifices (6, 7) provided in the well (1) wall (3), said orifices (6, 7) being arranged on either side of the liquid metal at places where the liquid metal (10) is not in contact with said wall (3).