摘要:
The method comprises the steps of: forming a porous fiber-reinforcing structure; introducing into the pores of the fiber structure powders containing elements for constituting the composite material matrix; and forming at least a main fraction of the matrix from said powders by causing a reaction to take place between said powders or between at least a portion of said powders and at least one delivered additional element; the powders introduced into the fiber structure and the delivered additional element(s) comprising elements that form at least one healing discontinuous matrix phase including a boron compound and at least one discontinuous matrix phase including a crack-deflecting compound of lamellar structure. At least a main fraction of the matrix is formed by chemical reaction between the powders introduced into the fiber structure and at least one delivered additional element, or by sintering the powders.
摘要:
A method of fabricating a friction part out of carbon/carbon composite material, the method including obtaining a three-dimensional fiber preform of carbon fibers impregnated with a solution or a suspension enabling a dispersion of refractory metal oxide particles to be left on the fibers of the preform; applying heat treatment to form a metallic carbide by a carboreduction reaction of the refractory oxide with the carbon of the fibers; continuing the heat treatment until the carbide is transformed into carbon by eliminating of the metal; and then densifying the preform with a carbon matrix by chemical vapor infiltration.
摘要:
The subject of the present invention is a method of obtaining fibrous carbon materials by carbonization of cellulosic fibrous materials carried out continuously or batchwise in the presence of at least one organosilicon compound. Characteristically, said organosilicon compound is chosen from the family of crosslinked, cyclic or branched oligomers and resins, which have a number-average molecular mass of between 500 and 10 000 and which consist of units of formula SiO4 (called Q4 units) and units of formula SiOxRy (OR′)z.
摘要翻译:本发明的主题是通过在至少一种有机硅化合物的存在下连续或间歇进行的纤维素纤维材料的碳化获得纤维状碳材料的方法。 特征地,所述有机硅化合物选自交联的,环状的或支链的低聚物和树脂的族,其数均分子量为500至10000,并且由式SiO 4的单元组成。 (称为Q 4 S单元)和式SiO x X(OR')z的单元。
摘要:
The present invention relates to: a novel process for the preparation of mesophasic polyborazylene. Said process is of particular value in that it affords a quality product from an appropriate polyborazylene, rapidly (virtually instantaneously), reproducibly and with a good yield. Furthermore, said process is easy to carry out. Said process comprises the preparation of polyborazylene by the polycondensation of borazine in a closed reactor and the addition, to said polyborazylene obtained by polycondensation, of a solvent selected from aromatic solvents, borazine solvents and mixtures thereof, mesophasic polyborazylene which is novel in that it is in the presence of a particular solvent and/or by virtue of its quality, the use of said polyborazylene of the invention, and/or prepared according to the invention, as a boron nitride precursor.
摘要:
A method of treating ceramic fibers based on metal carbide, the method including a first reagent gas heat treatment performed with at least one first reagent gas of the halogen type that chemically transforms the surface of the fiber to obtain a surface layer constituted mainly of carbon, and a second reagent gas heat treatment performed with at least one second reagent gas that eliminates the surface layer formed during the chemical transformation.
摘要:
A method of treating ceramic fibers based on metal carbide, the method including a first reagent gas heat treatment performed with at least one first reagent gas of the halogen type that chemically transforms the surface of the fiber to obtain a surface layer constituted mainly of carbon, and a second reagent gas heat treatment performed with at least one second reagent gas that eliminates the surface layer formed during the chemical transformation.
摘要:
A method of obtaining fiber textures of carbon from a cellulose precursor includes the steps of: spinning cellulose filaments (12) from a viscose solution or a cellulose solution; subjecting the cellulose filaments to washing in water (21); impregnating the washed and non-dried cellulose filaments with an aqueous emulsion (41) of at least one organosilicon additive; drying the impregnated cellulose filaments; and obtaining a fiber texture made up of impregnated and dried cellulose filaments prior to carbonization.
摘要:
The invention relates to a method of making a refractory carbide layer on the accessible surface of a C/C composite material, the method including a step consisting in placing the composite material in contact with a reactive composition in solid form that contains an atomic proportion greater than or equal to one-third and less than or equal to 95% of a metal that is a precursor of a determined carbide having a melting temperature greater than 2000° C., and an atomic proportion of silicon that is greater than or equal to 5% and less than or equal to two-thirds. The method further includes a step consisting in impregnating the accessible surface of the C/C composite material with the reactive composition melted at a temperature that is greater than or equal to the melting temperature of the metal that is a precursor of a determined carbide.
摘要:
A method of fabricating a friction part out of carbon/carbon composite material, the method including obtaining a three-dimensional fiber preform of carbon fibers impregnated with a solution or a suspension enabling a dispersion of refractory metal oxide particles to be left on the fibers of the preform; applying heat treatment to form a metallic carbide by a carboreduction reaction of the refractory oxide with the carbon of the fibers; continuing the heat treatment until the carbide is transformed into carbon by eliminating of the metal; and then densifying the preform with a carbon matrix by chemical vapor infiltration.
摘要:
The invention relates to a nuclear fuel cladding totally or partially made of a composite material with a ceramic matrix containing silicon carbide (SiC) fibers as a matrix reinforcement and an interphase layer provided between the matrix and the fibers, the matrix including silicon carbide as well as at least one of the following additional carbides: titanium carbide (TiC), zirconium carbide (Zrc), and ternary titanium silicon carbide (Ti3SiC2). When irradiated and at temperatures of between 800° C. and 1200° C., said cladding can mechanically maintain the nuclear fuel within the cladding while enabling optimal thermal-energy transfer towards the coolant. The invention also relates to a method for making the nuclear fuel cladding.
摘要翻译:本发明涉及一种全部或部分由复合材料制成的核燃料包层,该复合材料具有含有碳化硅(SiC)纤维作为基质增强层的陶瓷基体,以及设置在基质和纤维之间的相间层,该基体还包括碳化硅 作为以下附加碳化物中的至少一种:碳化钛(TiC),碳化锆(Zrc)和三元钛碳化硅(Ti 3 SiC 2)。 当照射并且在800℃和1200℃之间的温度下时,所述包层可以将核燃料机械地保持在包壳内,同时能够使朝向冷却剂的最佳热能传递。 本发明还涉及制造核燃料包层的方法。