Elastic properties and fracture toughness of SiOC-based glass-ceramic nanocomposites |
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| Authors: | Theany To Christina Stabler Emanuel Ionescu Ralf Riedel Fabrice Célarié Tanguy Rouxel |
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| Affiliation: | 1. Glass and Mechanics Department, Physics Institute, UMR UR1-CNRS 6251, University of Rennes 1, Rennes Cedex, France;2. Institut für Materialwissenschaft, Technische Universität Darmstadt, Darmstadt, Germany |
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| Abstract: | Four different SiOC glass ceramics were synthesized and their fracture toughness (KIc) and fracture surface energy (γ) were assessed by means of the single-edge precracked beam (SEPB) method. In addition, the elastic moduli were measured and the Vickers indentation behavior (hardness and microcracking) was characterized. In particular, the dependence of KIc on the free carbon content and on the fraction of crystallized nanoparticles (SiC, ZrO2, HfO2) was investigated. An increase in KIc, from about 0.73 to 0.99 MPa √m is observed as the free carbon content is increased from less than 1 to 12 vol%. The addition of Hf and Zr (resulting in 4.5 to 7.8 vol% HfO2 and ZrO2 nanoparticles) was found to increase KIc to an extent similar to the free carbon content. Moreover, predicted KIc values, assuming that the crack travels through all phases accounting for their respective volume fractions, disrupting the weakest links within the structural units, are in agreement with the experimental values. |
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| Keywords: | fracture toughness glass ceramic hafnium SEPB silicon oxycarbide zirconium |
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