Abstract:
A method for pressureless sintering of B 4 C without sintering agents which reduces sintering time without sacrificing relative density, and avoids decomposition of B 4 C and loss of relative density.
Abstract translation:没有烧结剂的B 4无压烧结方法,其可以降低烧结时间而不牺牲相对密度,并避免B 4 S C的分解和相对密度的损失。
Abstract:
A method for pressureless sintering of B 4 C without sintering agents which reduces sintering time without sacrificing relative density, and avoids decomposition of B 4 C and loss of relative density.
Abstract translation:用于无需烧结剂的B 4 C无压烧结的方法,其在不牺牲相对密度的情况下减少烧结时间,并避免B 4 C 并丧失相对密度。 p>
Abstract:
An oxidation resistant carbon fiber reinforced carbon composite material comprising a matrix and 20 vol.% or more of a carbon fiber, characterized in that the matrix comprises powdery ceramics containing at least a powdery boron carbide of 5mum or less average particle diameter, the powdery ceramics contained in an amount of 32 vol.% or more based on the volume of carbon fiber.
Abstract:
A brake component wherein at least a portion of said brake component is a ceramic metal composite (CMC), the CMC having an interconnected ceramic phase and a noncontiguous metal phase dispersed within the interconnected ceramic phase. In particular, a CMC of dense boron carbide-aluminum composite having high specific heat and low density is described.
Abstract:
A ceramic composite (10) comprises a transient plastic phase (12) and a reactant phase (14). The transient plastic phase (12) includes a metallic component and may also include a non-metallic component. Heat and pressure are applied to the ceramic composite (10) to plastically deform the transient plastic phase (12) of the composite (10) and densify the composite (10). The densified composite is heated to react the transient plastic phase (12) and the reactant phase (14) in the solid state at a reaction temperature lower than the melting temperature of either the transient plastic phase (12) or the reactant phase (14). A portion of the metallic component of the transient plastic phase (12) is transferred to a reinforcing phase (22) whereby a strengthened and toughened ceramic composite is formed comprising: (1) a matrix phase (20); and (2) a reinforcing phase (22) in the matrix phase (20).
Abstract:
Ultrafine, high purity B4C is produced by BCl3, CH4 or C2H4, and H2, using a CO2 laser (10), where a stoichiometric excess of H2 and about half the stoichiometric amount of CH4 or C2H4 is employed.
Abstract translation:使用CO2激光器(10)由BCl3,CH4或C2H4和H2生产超细高纯度B4C,其中使用化学计量过量的H 2和约一半化学计量量的CH 4或C 2 H 4。
Abstract:
Die Erfindung betrifft die Herstellung von kohlenstoffhaltigen keramischen Bauteilen mit einer Makrostruktur. Erfindungsgemäß wird ein Geliermittel enthaltender, wässriger Schlicker aus einem später graphitisierbaren Kohlenstoffträger und aus mindestens einer Oxidkörnung und/oder Nicht-Oxidkörnung in eine wässrige Härterlösung mit mindestens 0,05 Gew.% Metallkationen zur Gelierung gefördert und darin zu einem 2- oder 3-dimensionalen Bauteil geformt, wobei der wässrige Schlicker als Geliermittel ein Alginat mit einem Anteil von 0,1 bis 5 Gew.% des Feststoffgehaltes des wässrigen Schlickers enthält. Die resultierenden Bauteile können, je nach verwendetem Material, aufgrund ihrer großen Oberfläche für die Filtration von Fluiden, als Katalysator oder Katalysatorträger als wärmeübertragende Materialien eingesetzt werden.
Abstract:
This invention concerns a composite material comprising a hard ceramic matrix having molybdenum (Mo) particles incorporated therein, wherein the molybdenum content in the ceramic matrix is 1–10% by volume with respect of the composite material bulk. The invention also concerns a process for preparing such a composite material. This process comprises the steps of (a) mixing molybdenum powder with powder of ceramic matrix material, and (b) sintering the obtained powder mixture of molybdenum and ceramic matrix material. The invention further concerns a self- lubricating wear facing part suitable for use at temperatures in the range of 20–800°C, the wear facing part comprising at least a layer of, or being made of, a composite material according to the invention.
Abstract:
A method for densifying a porous substrate (50) by means of a matrix, said method comprising the steps of: - fractionation of the porosity present in the porous substrate in such a way as to form, in said substrate, a microporosity network, said fractionation being carried out with a filling composition comprising at least one carbon phase or one carbide phase accessible via the microporosity network, - reactive gaseous-phase chemical infiltration of the microporosity network formed by the filling material, said infiltration being carried out with a reactive gaseous composition free of carbon and comprising at least one element capable of reacting with the carbon of the filling composition in order to form a carbide (53).
Abstract:
The invention comprises a process comprising infiltrating or infiltrating and coating a substrate with a boron-comprising precursor, and contacting the boron-comprising precursor with a nitrogen-comprising reactant to convert the boron-comprising precursor to BN or other a boron-nitrogen reaction product in the surface porosity or in the surface porosity and on the surface of the substrate. Composite materials comprising as one phase a substrate and BN or other a boron-nitrogen reaction product as a further phase, in surface porosity or in surface porosity and on a surface of the substrate, are claimed.