摘要:
A refractory ceramic composite for an armor shell, comprising a ceramic core that is formable to replicate a portion of a three dimensional surface, e.g., of an aircraft, to provide ballistic protection. A method of making a shell of refractory ceramic armor capable of conforming to the geometry is provided. The shell is formed by forming a mold to replicate the surface area; arranging a ceramic core on the mold; and removing the mold to leave said ceramic core, and heat treating the ceramic core to a desired hardness. The ceramic core is in the shape of the surface area.
摘要:
A CMC article and process for producing the article to have a layer on its surface that protects a reinforcement material within the article from damage. The method entails providing a body containing a ceramic reinforcement material in a matrix material that contains a precursor of a ceramic matrix material. A fraction of the reinforcement material is present and possibly exposed at a surface of the body. The body surface is then provided with a surface layer formed of a slurry containing a particulate material but lacking the reinforcement material of the body. The body and surface layer are heated to form the article by converting the precursor within the body to form the ceramic matrix material in which the reinforcement material is contained, and by converting the surface layer to form the protective layer that covers any fraction of the reinforcement material exposed at the body surface.
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 said matrix and said fibers, the matrix including at least one carbide selected from titanium carbide (TiC), zirconium carbide (ZrC), or 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和在所述基质和所述纤维之间提供的界面层,该基质包括至少一种碳化物 选自碳化钛(TiC),碳化锆(ZrC)或三元钛碳化硅(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。
摘要:
A process for producing a silicon-containing CMC article that exhibits improved physical, mechanical, and microstructural properties at elevated temperatures exceeding the melting point of silicon. The process entails producing a body containing a ceramic reinforcement material in a solid matrix that comprises solid elemental silicon and/or silicon alloy and a ceramic matrix material. The ceramic matrix composite article is produced by at least partially removing the solid elemental silicon and/or silicon alloy from the solid matrix and optionally reacting at least part of the solid elemental silicon and/or silicon alloy in the solid matrix to form one or more refractory materials. The solid elemental silicon and/or silicon alloy is sufficiently removed from the body to enable the ceramic matrix composite article to structurally and chemically withstand temperatures above 1405° C.
摘要:
A string for use in a string ribbon crystal has a base portion with a refractory material, and an externally exposed layer radially outward of the refractory material. The base portion has a coefficient of thermal expansion that is generally matched with the coefficient of thermal expansion for silicon. The externally exposed layer has a contact angle with silicon of between about 15 and 120 degrees.
摘要:
A ceramic matrix composite with a ceramic matrix and a gradient layering of coating on ceramic fibers. The coating typically improves the performance of the composite in one direction while degrading it in another direction. For a SiC-SiC ceramic matrix composite, a BN coating is layered in a gradient fashion or in a step-wise fashion in different regions of the article comprising the ceramic. The BN coating thickness is applied over the ceramic fibers to produce varying desired physical properties by varying the coating thickness within differing regions of the composite, thereby tailoring the strength of the composite in the different regions. The coating may be applied as a single layer as a multi-layer coating to enhance the performance of the coating as the ceramic matrix is formed or infiltrated from precursor materials into a preform of the ceramic fibers.
摘要:
A composition providing thermal, corrosion, and oxidation protection at high temperatures is based on a synthetic aluminum phosphate, in which the molar content of aluminum is greater than phosphorus. The composition is annealed and is metastable at temperatures up to 1400° C.
摘要:
A fiber preform for constituting the fiber reinforcement of composite material is prepared and then consolidated by depositing sufficient matrix phase therein to bond the fibers together while not completely densifying the preform. Pins of rigid material are put into place through the consolidated preform and densification of the consolidated preform containing the pins is continued by depositing at least a ceramic matrix phase. Thereafter, at least a portion of each pin is eliminated so as to leave a calibrated perforation passing through the resulting part, the pins being made at least in part out of a material that can be eliminated by applying treatment that does not affect the ceramic material of the matrix.
摘要:
A method for reducing oxidation in ceramic composites is provided. The method includes depositing a first portion of a silicon carbide (SiC) matrix over at least a portion of an article using a first chemical vapor infiltration (CVI) process, depositing a silicon (Si)-doped boron nitride (BN) layer within at least a portion of the SiC matrix using a second CVI process, and depositing a second portion of the SiC matrix within at least a portion or continuation of the first portion of the SiC matrix using a third CVI process.
摘要:
A chemically doped boron coating is applied by chemical vapor deposition to a silicon carbide fiber and the coated fiber then is exposed to magnesium vapor to convert the doped boron to doped magnesium diboride and a resultant superconductor.