000008878 001__ 8878 000008878 005__ 20141204083529.0 000008878 04107 $$aeng 000008878 046__ $$k12/05/2014 000008878 100__ $$aŠín, P. 000008878 24500 $$aFRACTURE TOUGHNESS OF KAOLIN FIRED AT DIFFERENT TEMPERATURES 000008878 24630 $$n20.$$pEngineering Mechanics 2014 000008878 260__ $$bBrno University of Technology- Institute of Solid Mechanics, Mechatronics and Biomechanics 000008878 506__ $$arestricted 000008878 520__ $$2eng$$aThe fracture toughness (FT) test was performed at room temperature on ceramic samples made from kaolin at temperatures of 400–1250 °C at a heating and cooling rate of 5 °C/min. The precrack was made by indentation under the loads 10–200 N, the dwell time was 45 s and the loading rate was 10 N/s. Results of the FT tests were in accordance with the changes in structure of the samples after the partial firings. The FT from 20 °C to 500 °C is almost constant and it varies between 0.1 MPa·m0.5 and 0.2 MPa·m0.5. Dehydroxylation (420–600 °C) and solid state sintering (700–950 °C) does not influence the value of FT. At temperature interval where we assume liquid state sintering (1000–1250 °C) we observe an exponential increase of FT up to 0.6 MPa·m0.5. From comparison of FT, Young modulus and flexural strength, a correlation and proportionality of these mechanical properties follows. 000008878 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb. 000008878 653__ $$aFracture toughness, Mechanical strength, Sintering, Dehydroxylation. 000008878 7112_ $$aEngineering Mechanics 2014$$cSvratka (CZ)$$d12/05/2014 - 15/05/2014$$gEM2014 000008878 720__ $$aŠín, P.$$iSergejev, F.$$iŠtubňa, I. 000008878 8560_ $$ffischerc@itam.cas.cz 000008878 8564_ $$s294684$$uhttps://invenio.itam.cas.cz/record/8878/files/131-Sin-CD.pdf$$yOriginal version of the author's contribution as presented on CD, paper No. 131. 000008878 962__ $$r70 000008878 980__ $$aPAPER