摘要:
A method for manufacturing a silicon nitride substrate is provided. The method comprises the steps of: preparing a ceramic composition containing a metal silicon powder and a crystalline phase control powder containing a rare earth element-containing compound and a magnesium-containing compound; manufacturing a sheet-shaped molded body of a slurry prepared by mixing a solvent and an organic binder with the ceramic composition; and performing heat treatment including a nitrification section where heat treatment is performed at a first temperature in the range of 1300-1500° C. together with the application of nitrogen gas to the molded body at a predetermined pressure and a sintering section where heat treatment is performed at a second temperature in the range of 1700-1900° C.
摘要:
Ceramic composite materials that are reinforced with carbide fibers can exhibit ultra-high temperature resistance. For example, such materials may exhibit very low creep at temperatures of up to 2700° F. (1480° C.). The present composites are specifically engineered to exhibit matched thermodynamically stable crystalline phases between the materials included within the composite. In other words, the reinforcing fibers, a debonding interface layer disposed over the reinforcing fibers, and the matrix material of the composite may all be of the same crystalline structural phase (all hexagonal), for increased compatibility and improved properties. Such composite materials may be used in numerous applications.
摘要:
A method for forming a CMC article is disclosed, including forming a CMC precursor ply assembly. Forming the CMC precursor ply assembly includes laying up a plurality of CMC precursor plies and entraining a melt infiltration agent to form an entrained agent supply. Each of the plurality of CMC precursor plies includes a matrix precursor and a plurality of ceramic fibers. The plurality of CMC precursor plies and the entrained agent supply are arranged to form the CMC precursor ply assembly, which includes an article conformation. The method further includes carbonizing the CMC precursor ply assembly, infusing the melt infiltration agent from the entrained agent supply into the plurality of CMC precursor plies, and densifying the CMC precursor ply assembly with the melt infiltration agent to form the CMC article.
摘要:
A ceramic matrix composite includes a plurality of fibers embedded in a matrix. The composition of the matrix is selected to achieve a desired relationship between the mechanical and thermal properties of the matrix and the fibers.
摘要:
The invention relates to a granulated powder intended, in particular, for the production of ceramic sintered parts, said powder having the following chemical weight composition, based on dry matter, namely: at least 1% of a first binder having a glass transition temperature less than or equal to 25° C.; 0-4% of an additional binder having a glass transition temperature greater than 25° C.; 0-4% of a temporary additive different from the first binder and the additional binder, the total content of the first binder, the additional binder and the temporary additive being less than 9%; 0-15% of an additive for sintering the ceramic material; at least 2% impurities; and the remainder comprising a ceramic material, and optionally an agent for stabilizing said ceramic material, to make up 100%. According to the invention, the median diameter D50 of the powder is between 80 and 130 μm, the percentile D99.5 is less than 500 μm and the relative density of the granules is between 30% and 60%.
摘要:
There is disclosed a porous material. The porous material contains aggregates, and a bonding material which bonds the aggregates to one another in a state where pores are formed among the aggregates, the bonding material contains crystalline cordierite, the bonding material further contains a rare earth element or a zirconium element, and a ratio of a mass of the bonding material to a total mass of the aggregates and the bonding material is from 12 to 45 mass %. The bonding material preferably contains, in the whole bonding material, 8.0 to 15.0 mass % of MgO, 30.0 to 60.0 mass % of Al2O3, 30.0 to 55.0 mass % of SiO2, and 1.5 to 10.0 mass % of a rare earth oxide or zirconium oxide.
摘要翻译:公开了一种多孔材料。 多孔材料含有聚集体和在聚集体之间形成孔的状态下将聚集体彼此结合的接合材料,接合材料含有结晶堇青石,接合材料还含有稀土元素或锆元素,并且 接合材料的质量与聚集体和接合材料的总质量的比率为12〜45质量%。 接合材料优选在整个接合材料中含有8.0〜15.0质量%的MgO,30.0〜60.0质量%的Al 2 O 3,30.0〜55.0质量%的SiO 2和1.5〜10.0质量%的稀土类氧化物或氧化锆 。
摘要:
There is disclosed a porous material. The porous material contains aggregates, and a bonding material which bonds the aggregates to one another in a state where pores are formed among the aggregates, the bonding material contains crystalline cordierite, the bonding material further contains a rare earth element or a zirconium element, and a ratio of a mass of the bonding material to a total mass of the aggregates and the bonding material is from 12 to 45 mass %. The bonding material preferably contains, in the whole bonding material, 8.0 to 15.0 mass % of MgO, 30.0 to 60.0 mass % of Al2O3, 30.0 to 55.0 mass % of SiO2, and 1.5 to 10.0 mass % of a rare earth oxide or zirconium oxide.
摘要翻译:公开了一种多孔材料。 多孔材料含有聚集体和在聚集体之间形成孔的状态下将聚集体彼此结合的接合材料,接合材料含有结晶堇青石,接合材料还含有稀土元素或锆元素,并且 接合材料的质量与聚集体和接合材料的总质量的比率为12〜45质量%。 接合材料优选在整个接合材料中含有8.0〜15.0质量%的MgO,30.0〜60.0质量%的Al 2 O 3,30.0〜55.0质量%的SiO 2和1.5〜10.0质量%的稀土类氧化物或氧化锆 。
摘要:
The present invention relates to a method of manufacturing a porous pre-sintered granule for a sintered reaction-bonded silicon nitride, to which a pressure forming technology can be applied to obtain a porous sintered reaction-bonded silicon nitride having high porosity and having a structure in which macropores and micropores coexist with each other, and to a porous pre-sintered granule manufactured by the method. The method includes the steps of: granulating a raw material comprising silicon and sintering additives including yttrium, aluminum and at least one alkali earth metal compound; and pre-sintering the granulated raw material at a temperature of 1300˜1375° C. under an inert atmosphere. According to the present invention, a porous pre-sintered granule for porous sintered reaction-bonded silicon nitride, which can increase the air permeability and trapping efficiency by controlling the size of a pore channel such that macropores and micropores coexist, can be manufactured.
摘要:
Disclosed is a porous sintered reaction-bonded silicon nitride ceramic, which includes an array of sintered granules having fine pore channels in the sintered granules and coarse pore channels formed between the sintered granules, and in which the pore channel size is controlled so that both coarse pores and fine pores are formed together in the ceramic, thus simultaneously enhancing air permeability and capturing efficiency. A method of manufacturing the porous sintered reaction-bonded silicon nitride ceramic is also provided.
摘要:
The disclosed invention relates to a biodegradable grease composition. The grease composition comprises the reaction product of a dispersion of metal oxide and/or hydroxide particulates with at least one animal or vegetable oil. The dispersion comprises an organic medium and has a water content of up to about 0.5% by weight water. The particulates have a mean particle size up to about 15 microns. A process for making a grease composition using a dispersion of metal oxide and/or hydroxide particulates is disclosed.