Consolidation features of ZTA-composite with eutectic composition

DOI: 10.62564/M4-IM1226

Olena Dudnik¹, Iryna Marek¹, Maria Smirnova-Zamkova¹, Victor Red'ko¹, Iryna Martsenyuk¹, Viktor Gerashchenko², Tetyana Mosina¹, Olexiy Ruban<sup>1

1</sup>Frantsevich Institute for Problems of Materials Science National Academy of Science of Ukraine
²V. Bakul Institute for Superhard Materials of the National Academy of Sciences of Ukraine


ZTA are ceramics in the Al2O3–ZrO2–Y2O3–CeO2 system, which are characterized by high-temperature mechanical strength, heat resistance, wear resistance, oxidation resistance, low thermal conductivity, as well as a small ratio between the coefficients of thermal expansion of ZTA and metals [1]. The mechanical properties of ceramics depend mainly on the amount of ZrO2, its grain size, as well as the ratio of T-ZrO2 and M-ZrO2 and their location in the Al2O3 matrix. ZTA with a composition close to the Al2O3–ZrO2 eutectic are considered as a promising ceramics. The purpose of the research is to determine the consolidation features of the ZTA composite containing 58.5% (wt.) ZrO2 (Y2O3, CeO2). The composition of a solid solution based on ZrO2 (ZrO2 (Y2O3, CeO2)) (mol.%) is 90 ZrO2–2Y2O3–8 CeO2. Cold uniaxial pressing were used for the green bodies formation. Sintering was carried out in the Nabertherm LTH08/17 laboratory electric furnace at 1500 °С, 2 hours. Grinds of sintered samples longitudinal sections were made to determine of Vickers hardness. Sintered materials were investigated by X-ray phase analysis (XRF) and scanning electron microscopy. The Vickers hardness was measured using a "Falkon 509" hardness tester (manufactured in the Netherlands) with an indenter load of 300 N (30 kg). The relative density of green bodies 0.46. The relative density of sintered samples was up to 0.97. Phase composition – T-ZrO2, α-Al2O3. A certain orientation of Al2O3 grains was found observed in homogeneous areas, which is a manifestation of the ceramics "topochemical memory", since the composition of the composites corresponds to the eutectic of the binary system Al2O3–ZrO2. Microhardness was 190 MPa, Vickers hardness reached 3.7 GPa, K1c = 7 MPa m 0.5. Using of improved approaches under consolidation of the ZTA eutectic composition will help improve their mechanical characteristics under the microstructural design of high-tech instrumental, structural and functional ceramics.

Keywords
ZTA composites, consolidation features,T-ZrO2, α-Al2O3.

Acknowledgments
Not provided

References
[1] Otitoju T. A., Okoye P. U., Chen G., Li Y., Okoye M. O., Li S., Advanced ceramic components: Materials, fabrication, and applications. Journal of Industrial and Engineering Chemistry.2020.Vol. 85. P.34–65 https://doi.org/10.1016/j.jiec.2020.02.002