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Registration Number

0222U004599, 0117U002205 , R & D reports

Title

Nanocomposites besed on SiC and Si3N4 with selfhealing structure defects function for ceramic friction parts, corrosive resistant coverages and heatsinks of long duration exploitation

Head

Ragulya Andrii V., Доктор технічних наук

Registration Date

19-09-2022

Organization

Institute of Problems of Materials Science named after IM Frantsevich of the National Academy of Sciences of Ukraine

Description

 The conditions of SPS consolidation of the composites of ZrN-Si 3 N 4 and Si 3 N 4 -ZrN-TiN systems have been studied. It was found that the compaction of the Si 3 N 4 -ZrN-TiN system intensifies nanocrystalline TiN at T ~ (1100-1300) С. Mechanical properties of ZrN-Si 3 N 4 -TiN composites were found to be higher than of Si 3 N 4 -ZrN-based composites. Composites with 15% and 30 wt.% of TiN exhibited HV 10 = 20 ÷ 22 GPa, K 1c = 5,2÷5,8 МПа·м 1/2 , respectively. The amount of ZrN in the composite, the composition of the counter-body (BK6 or Si3N4), and their physicochemical interaction influence on the tribological properties. The effect of self-healing of a surface defects Si 3 N 4 -ZrN-TiN has been studied as follows. During dry friction - by oxidation to SiО 2 or Si(ОН) 2 , which acts as a solid lubricant. Friction in saline - the formation of tribo- layers Zr(ОН) 2 and Ti(ОН) 2 . Friction at a temperature of ~ 550 ℃ - formation of regenerating ZrO 2 . SiC-Si 3 N 4 -Si 2 N 2 O ceramic been produced via HP method with sintering activators. The optimal compositions and the reaction consolidations regime of ceramics with a homogeneous highly dispersed structure and with composite grain boundaries have been established. The effect of formation of metal-like structures in the intergranular layers, which influence the electrophysical and tribological characteristics of ceramics, been revealed. The principle of creating the new functional element based on oxygen-free refractory compounds for high-temperature thermoelectric generators of thermo-EDF and voltage is realized by formation of new phases during in situ high-temperature consolidation. It had been shown that in such dispersed composites at the concentration of the conductor close to the percolation threshold there is a transverse thermo EDF, which is anisotropy of thermal conductivity and results in a transverse temperature difference, and, as a consequence, eddy currents.

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Itsenko Anatolii I.
Borodianska Hanna Yu.
Gadzyra Mykola P.
Haliamin Volodymyr B.
Grinkevуch Kostyantyn E.
Davydchuk Nadiya K.
Derii Andrii I.
Zamula Maryna V.
Zgalat-Lozynskyy Ostap B.
Zyatkevych Dmytro P.
Kozak Svitlana I.
Kolesnichenko Valerii H.
Kushnir Vladyslav V.
Lazhevskyi Viktor O.
Monakina Diana M.
Pinchuk Мykyta O.
Petrovsky Vitaly Ya.
Petukhov Oleksandr S.
Pokhylko Bohdan A.
Ragulya Andrii V.
Semeniuk Nataliia G.
Tepliuk Olena V.
Tymoshenko Yaroslav G.
Tyshchenko Nadiya I.
Tkachenko Ivan V
Shulzhenko Volodymyr Ya.