1.1 This document is a guide to preparing material specifications for silicon-carbide fiber/silicon carbide matrix (SiC-SiC) composite structures (flat plates, rectangular bars, round rods, and tubes) manufactured specifically for structural components and for fuel cladding in nuclear reactor core applications. The SiC-SiC composites consist of silicon carbide fibers (from PAN, pitch, or rayon precursors) in a silicon carbide matrix produced by liquid infiltration/pyrolysis and/or by chemical vapor infiltration. 1.2 The guide consists of two sections: 1) a classification system (based on fiber and matrix constituents, fiber architecture, physical properties, and mechanical properties) and 2) guidance on the development of specifications for SiC/SiC composite structures. The specification guide considers composite constituents and structure, physical and chemical properties, mechanical properties, thermal properties, performance durability, methods of testing, materials and fabrication processing, and quality assurance. The SiC-SiC composite materials considered here would be suitable for nuclear reactor core applications where neutron irradiation-induced damage and dimensional changes are a significant design consideration. (Ref. 1-8). 1.3 This guide provides direction and guidance for the development of a material specification for a specific SiC-SiC composite component or product for nuclear reactor applications. The component specification is to be developed by the designer/purchaser/user. The designer/purchaser/user shall define and specify in detail any and all application-specific requirements for necessary design, manufacturing, and performance factors of the ceramic composite component This guide for material specifications does not directly address component/product-specific issues, such as geometric tolerances, permeability, bonding, sealing, attachment, and system integration. . 1.4 This specification guide is specifically focused on SiC-SiC composite components and structures with flat plate, solid rectangular bar, solid round rod, and tubular geometries. 1.5 This specification guide may also be applicable to SiC-SiC composites used for other structural applications, discounting the nuclear-specific chemical purity and irradiation behavior requirements. 1.6 Units - The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
This document is needed to provide guidance and direction on specifying, producing, and qualifying silicon carbide-silicon carbide composites for use as structural components in nuclear reactors. This specification will be used by government regulatory agencies, standards development organizations, nuclear power OEMs, and CMC producers for design,
KeywordsSilicon carbide composites; silicon carbide fiber; nuclear reactor; mechanical properties; physical properties; thermal properties; chemical properties; durability; fabrication; processing.
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top