摘要:
A multi-layered cladding material including a ceramic matrix composite and a metallic material, and a tube formed from the cladding material. The metallic material forms an inner liner of the tube and enables hermetic sealing of thereof. The metallic material at ends of the tube may be exposed and have an increased thickness enabling end cap welding. The metallic material may, optionally, be formed to infiltrate voids in the ceramic matrix composite, the ceramic matrix composite encapsulated by the metallic material. The ceramic matrix composite includes a fiber reinforcement and provides increased mechanical strength, stiffness, thermal shock resistance and high temperature load capacity to the metallic material of the inner liner. The tube may be used as a containment vessel for nuclear fuel used in a nuclear power plant or other reactor. Methods for forming the tube comprising the ceramic matrix composite and the metallic material are also disclosed.
摘要:
Methods of producing continuous boron carbide fibers. The method comprises reacting a continuous carbon fiber material and a boron oxide gas within a temperature range of from approximately 1400° C. to approximately 2200° C. Continuous boron carbide fibers, continuous fibers comprising boron carbide, and articles including at least a boron carbide coating are also disclosed.
摘要:
Methods of forming composite bodies and materials including a metal oxide, such as, uranium dioxide, and silicon carbide are disclosed. The composite materials may be formed from a metal oxide powder, a silicon carbide powder and, optionally, a carbon powder. For example, the metal oxide powder, the silicon carbide powder and the carbon powder, if present, may each be combined with a binder and may be deposited in succession to form a precursor structure. Segments of the precursor structure may be removed and pressed together to form a multi-matrix material that includes interlaced regions of material including at least one of the metal oxide powder, the silicon carbide powder and, optionally, the carbon powder. The segments may be extruded or coextruded with another material, such as, a silicon carbide material, to form a green body. The green body may be sintered to form the composite bodies and materials having a desired final density.
摘要:
Methods of producing silicon carbide fibers. The method comprises reacting a continuous carbon fiber material and a silicon-containing gas in a reaction chamber at a temperature ranging from approximately 1500° C. to approximately 2000° C. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.01×102 Pascal to produce continuous alpha silicon carbide fibers. Continuous alpha silicon carbide fibers and articles formed from the continuous alpha silicon carbide fibers are also disclosed.
摘要:
Methods of producing silicon carbide fibers. The method comprises reacting a continuous carbon fiber material and a silicon-containing gas in a reaction chamber at a temperature ranging from approximately 1500° C. to approximately 2000° C. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.01×102 Pascal to produce continuous alpha silicon carbide fibers. Continuous alpha silicon carbide fibers and articles formed from the continuous alpha silicon carbide fibers are also disclosed.
摘要:
A multi-layered cladding material including a ceramic matrix composite and a metallic material, and a tube formed from the cladding material. The metallic material forms an inner liner of the tube and enables hermetic sealing of thereof. The metallic material at ends of the tube may be exposed and have an increased thickness enabling end cap welding. The metallic material may, optionally, be formed to infiltrate voids in the ceramic matrix composite, the ceramic matrix composite encapsulated by the metallic material. The ceramic matrix composite includes a fiber reinforcement and provides increased mechanical strength, stiffness, thermal shock resistance and high temperature load capacity to the metallic material of the inner liner. The tube may be used as a containment vessel for nuclear fuel used in a nuclear power plant or other reactor. Methods for forming the tube comprising the ceramic matrix composite and the metallic material are also disclosed.
摘要:
Fuel elements for use in reactors include a cladding tube having a longitudinal axis and fuel disposed therein. At least one channel is formed in at least one of the fuel and the cladding tube and extends in a direction along the longitudinal axis of the cladding tube. The fuel element further includes a plenum having at least one getter material disposed therein. Methods of segregating gases in fuel elements may include forming a temperature differential in the fuel element, enabling at least one gas to travel into at least one channel formed in the fuel element, and retaining a portion of the at least one gas with at least one getter material. Methods of segregating gases in fuel elements also may include enabling at least one gas to travel through at least one channel of a plurality of channels formed in the fuel element.
摘要:
Methods of producing continuous boron carbide fibers. The method comprises reacting a continuous carbon fiber material and a boron oxide gas within a temperature range of from approximately 1400° C. to approximately 2200° C. Continuous boron carbide fibers, continuous fibers comprising boron carbide, and articles including at least a boron carbide coating are also disclosed.
摘要:
The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) of reinforcement materials in composite bodies. In a preferred embodiment of the invention, a coated ceramic filler material adaptable for use as a reinforcing component in a ceramic matrix composite is provided with a plurality of superimposed coatings. The coating system includes a first coating in substantially continuous contact with the ceramic filler material and one or more additional or outer coatings superimposed over the underlying coating and in substantially continuous contact therewith. Zonal junctions are formed between the filler and the first coating, between superimposed coatings, and between the outer coating and the ceramic matrix. The coatings are selected so that the interfacial shear strength of at least one of these several zones is weak relative to the other zones. Upon the application of fracture stress to the composite, the weak zone allows for debonding of the filler before the filler fractures, and pull-out or shear of the filler upon fracture of the filler. This debonding and friction pull-out enhances certain mechanical properties of the composite, and in particular, debonding improves the fracture toughness.
摘要:
The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) of reinforcement materials in composite bodies. The oxidation protection mechanisms include getterer materials which are added to the composite body which gather or scavenge undesirable oxidants which may enter the composite body. The getterer materials may be placed into at least a portion of the composite body such that any undesirable oxidant approaching, for example, a fiber reinforcement, would be scavenged by (e.g., reacted with) the getterer. In a preferred embodiment of the present invention, the getterer material(s) form at least one compound (e.g., at least one glassy material) which acts as a crack sealant, thereby further enhancing the oxidation protection of the composite body. One or more ceramic filler materials which serve as reinforcements may have a plurality of superimposed coatings thereon, at least one of which coatings may function as a getterer. The coated materials may be useful as reinforcing materials in ceramic matrix composites to provide improved mechanical properties such as fracture toughness. The present invention also relates to improved composites which incorporate these materials, and to their methods of manufacture.