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Information × Registration Number 0222U000728, 0120U100665 , R & D reports Title Development of additive technologies and consolidation of ceramic nanocomposites under the influence of external electromagnetic fields popup.stage_title Head Ragulya Andrii V., Доктор технічних наук Registration Date 18-01-2022 Organization Institute of Problems of Materials Science named after IM Frantsevich of the National Academy of Sciences of Ukraine popup.description2 Radio-transparent ceramic based on Si3N4 and Si3N4–BN been obtained. It shows radio-transparency in frequency range 8–12,2 GHz (attenuation <2 dB), dielectric constant in the range of 6,2–8,1, and low tangent of the dielectric losses (<2·10-3). It was found, that all additives reduce ε of Si3N4 ceramics according to their bulk content in the composite. Thus, Si3N4 –BN ceramic with 10% of residual porosity showed ε ~ 6,5. Dense, poreless Si3N4 –Si2N2O composite and same composite with ~30% of residual porosity, showed ε~4,8, and ε~3,8 respectively. Full dense Si3N4–Si2N2O– BN ceramic exhibits ε=3,7. Si3N4 -based composites exhibit high room-temperature flexural strength of ~ 1000MPa, and ~400 MPa at 1400C. Their hardness and fracture toughness were ~15,3GPa and ~5,5MPa·m1/2, respectively. Such properties correspond to the current level of requirements for Si3N4-based ceramic. The 3D printing of bulk samples from Si3N4–Y2O3 nanopowders was performed by Binder Jetting and Robocasting methods. The criteria of feasibility of suspensions for printing been established from rheological analysis data. The relationship between their chemical composition and properties was analyzed as well. Samples of complex shape were obtained by both methods, and, then, been consolidated by the SPS method. To ensure uniform pressure transfer during sintering, the experimental technique of applying auxiliary graphite powder-backfill (quasi-isostate) was developed. For sintering by direct induction heating, a nanocomposite powder mixture based on of SiC and MAX phase Ti3SiC2, which the minimum share of 30 mass %, was created. It is shown that the formed induction generation of composite conductivity provides the realization of power up to 35 kW with a frequency of 2,5 kHz. Induction sintering of the created nanocomposite at a temperature of 1900°C is accompanied with formation of structure with a micrometer-size agglomerates, with 150 % enhancement of electrical conductivity. Product Description popup.authors Ivanchenko Serhii E. Itsenko Anatolii I. Bаrаnovskyi Dmytro I. Bondarenko Serhii O. Borodianska Hanna Yu. Gadzyra Mykola P. Haliamin Volodymyr B. Davydchuk Nadiya K. Derii Andrii I. Domikhina Nataliia V. Zamula Maryna V. Kovalenko Olha A. Kovalchuk Volodymyr V. Kozak Svitlana I. Kolesnichenko Valerii H. Kornienko Oksana A. Korop Serhii M. Koriak Oksana S. Kravchuk Karyna L. Kuzmenko Liudmyla M. Kulakov Sergii A. Kutran Tamara M. Kushnir Vladyslav V. Lazhevskyi Viktor O. Lobunets Tetiana F. Makohon Viktor A. Monakina Diana M. Pinchuk Мykyta O. Patsui Viktor I. Petrovsky Vitaly Ya. Petukhov Oleksandr S. Poznii Anatolii P. Pokhylko Bohdan A. Ragulya Andrii V. Semeniuk Nataliia G. Stepanenko Artur V. Tepliuk Olena V. Tymoshenko Yaroslav G. Tyshchenko Nadiya I. Tomila Tamara V. Tulinova Alla S. Fatov Ihor I. Shуrokov Oleksandr V. Shulzhenko Volodymyr Ya. Yurchenko Yuriy V. popup.nrat_date 2022-03-09 Close