Standards and codes for ceramic matrix composites

Ceramic matrix composites (CMCs) and, in particular, continuous fibre ceram ic composites (CFCCs) are targeted for industrial, aerospace and other high -technology applications that require the high-temperature properties and t he wear/corrosion resistance of advanced ceramics while providing inherent damage tolerance (i.e. increased 'toughness') without the volume/surface ar ea-dependent strengths of monolithic ceramics. To utilize CFCCs designers n eed reliable and comprehensive data bases (and the design codes that contai n them). Generating reproducible information for these data bases requires standards. Presently, there are relatively few (compared to metals) nationa l (e.g. ASTM, CEN, JIS, etc.) or international standards (e.g. ISO) for tes ting CFCCs. In this paper, the various standards for CFCCs are reviewed and additional areas requiring normalization are discussed (e.g. mechanical, t hermal, electrical, electro-magnetic, optical, and biological testing). 'De sign codes' such as the ASME Boiler and Pressure Vessel Code discussed here , are widely accepted, general rules for the construction of components or systems (for performance, efficiency, usability, or manufacturabilty) with emphasis on safety. Wide-ranging codes incorporate figurative links between materials, general design, fabrication techniques, inspection, testing, ce rtification, and finally quality control to insure that the code has been f ollowed. Implicit in design codes are many of the standards for materials t esting, characterization, and quality control. Logical outcomes of design c odes are data bases of material properties and performance 'qualified' for inclusion in the code. As discussed in this paper, data bases (such as thos e contained in the Mil-Hdbk-17 CMC effort) may be in print, electronic or w orldwide web-based formats and may include primary summary data (e.g. mean, standard deviation, and number of tests) along with secondary data (e.g. g raphical information such as stress-strain curves).