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Fracture Toughness Studies on Ceramics and Ceramic Particulate Composites at Different Temperatures Pages: 14 Published: Jan 2002
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View License Agreement Source: STP1409-EB Abstract The fracture toughness of alumina, zirconia, silicon nitride, and silicon carbide ceramics as well as silicon nitride and silicon carbide particulate composites were studied by the single edge V-notched beam (SEVNB) method over a wide temperature range. Manual and mechanical procedures for V-notch polishing-out and three- and four- point flexure tests were developed. Loaddeflection diagrams for V-notched specimens contributed to better understanding of the deformation behavior of ceramics at room temperature and 13001400 °C. SENB (single edge notched beam) and SEPB (single edge precracked beam) as well as micro-Raman spectroscopy data were used to analyze the SEVPB results. The ratio between SEVNB and SENB results is about 0.6 for elastic materials and over 0.9 for inelastic ones. The results for zirconia, in the case of a V-notch root radius less than 5-7 m, are in good agreement with SEPB results. The polishing-out of a V-notch does not lead to the tetragonalmonoclinic phase transformation in these materials.
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