主 題：Temperature Dependence of Young’s Modulus and Damping of Oxide and Silicate Ceramics and Refractories
主講人：Prof. Willi Pabst
The high-temperature mechanical behavior of ceramics and refractories is determined by both elastic and anelastic contributions. While the elastic properties determine the high-temperature stiffness and thermal shock resistance of these materials, damping reflects certain deviations from elastic behavior in the vibrational response of these materials that are indicative of dissipative processes. Both elastic properties and damping are principally dependent on the phase composition, microstructure (especially the content of pores and microcracks), and temperature. While the phase composition and microstructure determines the absolute values of the elastic properties and damping, the temperature dependence of these properties often reveals phase transitions and subtle microstructural features. This contribution summarizes results of high-temperature impulse excitation measurements for several important classes of oxide and silicate refractory ceramic materials (alumina- and zirconia-based ceramics, mullite-based ceramics, kaolin- and talc-based ceramics, and silica refractories). The results indicate that the temperature dependence of the Young’s modulus is not always monotonic and reversible, but may exhibit characteristic non-monotonic features due to phase transitions and hysteresis loops between heating and cooling (with or without damage accumulation) because of microcrack closure and re-opening. The temperature dependence of damping exhibits a comparable complexity. It is shown that the temperature dependence of Young’s modulus and damping is particularly interesting for silica refractories, that the presence of cristobalite is easily revealed from the temperature dependence of Young’s modulus and that the temperature dependence of damping can serve as a very sensitive probe providing additional information on phase transitions that may not be evident from the temperature dependence of elastic properties.
Willi Pabst 教授本科彩票网上购买恢复了吗、碩士畢業于德國的University of Tübingen，98年獲得捷克Institute of Chemical Technology (ICT Prague) 的工學博士學位，自93年開始就在ICT Prague（為現在的UCT Prague）工作至今?，F在為UCT Prague 大學的全職教授。Willi Pabst教授多年來專注于材料的結構研究，尤其是多孔材料的結構與性能的研究。自己著有書籍1本，合作著有書籍7本，發表學術論文70余篇彩票网上购买恢复了吗，WOS他引728次，H指數為24。
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