Issue 43

M. Davydova et alii, Frattura ed Integrità Strutturale, 43 (2018) 106-112; DOI: 10.3221/IGF-ESIS.43.08 106 The effect of porosity on fragmentation statistics of dynamically loaded ZrO 2 ceramics Marina Davydova, Sergei Uvarov, Oleg Naimark Institute of Continuous Media Mechanics Ural Branch Russian Academy of Sciences, 1, Ac. Korolev str., Perm 614013, Russia. 1957davydova@gmail.com, http://lab13.icmm.ru/index.php/en/ pia@icmm.ru, http://lab13.icmm.ru/index.php/en/ naimark@icmm.ru, http://lab13.icmm.ru/index.php/en/ A BSTRACT . The effect of load intensity and porous material structure on the fragmentation statistics of ZrO 2 (MgO)-based ceramics is studied. Cylindrical samples were fragmented under dynamic compression. Experimental data processing showed that the shape of stress-strain curves, the fragment size distribution and distribution of time intervals between the fractoluminiscense impulses depend on the sample porosity and load intensity. The X-ray Computed Tomography (CT) study of porous material structures allowed us to link the fragmentation statistics with pronounced porosity clustering (about 97% of the total pore volume) formed due to sintering. K EYWORDS . Fragmentation; Ceramic; Crack cluster. Citation: Davydova, M., Uvarov, S., Naimark, O., The effect of sample porosity on statistical regularities of dynamical fragmentation of ceramic ZrO 2 , Frattura ed Integrità Strutturale, 43 (2018) 106-112. Received: 17.10.2017 Accepted: 28.10.2017 Published: 01.01.2018 Copyright: © 2018 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION ynthesis of ceramic materials with projected properties implies studying the relationship between physical and mechanical characteristics and porosity of the material. On the one hand, the role of porosity as the main structural factor is associated with the absence of the effective mechanism of structural relaxation due to a dislocation motion, and, on the other hand, with the long–range interactions in the ensemble of pores growing during the deformation. These features determine the pore clustering, damage-failure kinetics and mechanical properties in a wide range of load intensity [1]. Study of the effect of porosity revealed the influence of the porous cluster morphology on the deformation properties of ceramics ZrO 2 (Y 2 O 3 ) [1,2]. This is associated with a change in pore distributions related to the transition from the isolated pore structure to the structure with pore clustering. In this paper, the effect of pore cluster morphology of the ceramic material subject to dynamic loading and fragmentation was studied based on the analysis of 2D and 3D structure images obtained by X-ray Computed Tomography (CT). S AMPLES AND EXPERIMENTAL TECHNIQUE he samples used in the experiment were fabricated at the Institute of Strength Physics and Material Sciences (SB RAS, Tomsk) from the ceramics of ZrO 2 -MgO system (8.6 % mol MgO) by the plasmochemical method [4]. The manufacture of ceramic samples was carried out by powder metallurgy technique, which consisted in powder S T