PSI - Issue 23

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Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000 – 000 Structural Integrity Procedia 00 (2019) 000 – 000

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Procedia Structural Integrity 23 (2019) 431–438

© 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the ICMSMF organizers nanosheet shear delamination (interlayer sliding). © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the IC MSMF organizers Keywords: carbon nanotubes; graphen; boron nitride nanotubes; boron nitride nanosheets; glass; alumina; ceramic matrix composites; fracture toughness; l ost positive effect of the nano-fillers has been confir ed for carbon nanotube, graphen, boron-nitride nanotubes and nanosheets. It has been effective thanks to elastic defor ation energy dissipation thanks to several toughening echanis s like crack deflection and bridging, pull-out being conditioned by good bonding of the filler to cera ic/glass atrix. T o toughening echanis s specific for the applied nano-reinforce ents have been recognised: telescopic pull-out (s ord-in-sheath) and nanosheet shear dela ination (interlayer sliding). 2019 The uthors. Published by Elsevier . . This is an open access article under the - - license (http://creativeco ons.org/licenses/by-nc-nd/4.0/) Peer-revie under responsibility of th scientific co ittee of the I S F organizers Keywords: carbon nanotubes; graphen; boron nitride nanotubes; boron nitride nanosheets; glass; alu ina; cera ic atrix co posites; fracture toughness; The aim of the contribution is to provide a view inside the current state of the art on the real effect of nanoscale fillers incorporated into glass and/or ceramic matrix on fracture resistance of the composite. The investigated materials included model composites based on silica and borosilicate glass matrices, and, in addition, also exploiting common ceramic matrices like alumina or zirconia. The nano-fillers, i.e. carbon and boron nitride nanotubes, graphen and boron nitride nanosheets have been explored in different volume fractions in order to analyse experimentally their quantitative effect on toughening mechanisms. The fracture toughness, K IC , was evaluated applying mainly chevron notch technique. Fracture surfaces were also analysed to get exact imagination about fracture micromechanisms acting during crack propagation. Almost positive effect of the nano-fillers has been confirmed for carbon nanotube, graphen, boron-nitride nanotubes and nanosheets. It has been effective thanks to elastic deformation energy dissipation thanks to several toughening mechanisms like crack deflection and bridging, pull-out being conditioned by good bonding of the filler to ceramic/glass matrix. Two toughening mechanisms specific for the applied nano-reinforcements have been recognised: telescopic pull-out (sword-in-sheath) and The ai of the contribution is to provide a vie inside the current state of the art on the real effect of nanoscale fillers incorporated into glass and/or cera ic atrix on fracture resistance of the co posite. The investigated aterials included odel co posites based on silica and borosilicate glass atrices, and, in addition, also exploiting co on cera ic atrices like alu ina or zirconia. The nano-fillers, i.e. carbon and boron nitride nanotubes, graphen and boron nitride nanosheets have been explored in different volu e fractions in order to analyse experi entally their quantitative effect on toughening echanis s. The fracture toughness, IC , as evaluated applying ainly chevron notch technique. Fracture surfaces ere also analysed to get exact i agination about fracture icro echanis s acting during crack propagation. 9th International Conference on Materials Structure & Micromechanics of Fracture Nano-fillers (nanotubes, nanosheets): do they toughen brittle matrices? Ivo Dlouhy a *, Peter Tatarko b , Luca Bertolla a , Zdenek Chlup a a Institute of Physics of Materials, CAS, Zizkova 22, Brno, Czech Republic b Institute of Inorganic Chemistry, SAS, Dubravska Cesta 9, Bratislava, Slovak Republic t I ter ati al fere ce aterials tr ct re icr ec a ics f ract re ill t , t : t t ittl t i I l a *, P t r t r b , rt ll a , l p a a Institute of Physics of aterials, CAS, Zizkova 22, Brno, Czech Republic b Institute of Inorganic Che istry, SAS, ubravska Cesta 9, Bratislava, Slovak Republic Abstract bstract

* Corresponding author. Tel.: +420 532 290 342. E-mail address: idlouhy@ipm.cz * Corresponding author. Tel.: +420 532 290 342. E- ail address: idlouhy ip .cz

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the IC MSMF organizers 2452-3216 2019 The uthors. Published by Elsevier B. . This is an open access article under the CC B - C- license (http://creativeco ons.org/licenses/by-nc-nd/4.0/) Peer-revie under responsibility of the scientific co ittee of the IC S F organizers

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the ICMSMF organizers 10.1016/j.prostr.2020.01.125