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Improved mechanical properties of alumina (Al2O3) and alumina based ceramics are required due to the widespread application of these materials for high-temperature and wear-resistant components of critical equipment in aircraft, power generation, dentistry, and other industries. The purpose of this work was to evaluate the impact of the phase composition of the alumina based ceramics sintered with adding small amounts of sintering aids on resulting mechanical properties. The initial Al2O3 powder was mixed with various additives (MgO, K2O, CaO, CrO2, Fe2O3, PdO, La2O3) to improve its sintering ability and provide high mechanical and functional characteristics of sintered ceramics. The samples were sintered in a nitrogen atmosphere. The sintering temperature was set to 1850 °C while the isothermal holding time was set to 1–2 h. The microstructure and phase composition analyses, as well as the study of mechanical properties of ceramic samples, were carried out. Namely, the Vickers indentation and flexure tests were performed and values of microhardness, fracture toughness, and flexural strength of ceramics were estimated. All the material variants consisted of α-Al2O3 as the dominant phase and small amounts of secondary phases. In the sintering process, the phase of CaAl12O19 type was formed along with the dominant α-Al2O3 phase when adding small amounts of CaO, MgO, PdO, and/or other oxide nanopowders to the initial Al2O3 powder. Finally, a fine-grained ceramic microstructure was obtained. The optimum combination of strength, microhardness, and fracture toughness providing high reliability of alumina based ceramics was found for ceramic samples containing the matrix α-Al2O3 phase and the minor phase of CaAl12O19 type.

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Study of the Chemical Composition Related Phase Balance in Fine-Grained Alumina Based Ceramics: An Impact on Mechanical Properties

  • 会议论文

  • 发表日期：

    2026年

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  • V. V. Kulyk,
  • Z. A. Duriagina,
  • B. D. Vasyliv,
  • N. R. Kliuchkovska,
  • P. Y. Lyutyy,
  • A. M. Trostianchyn,
  • V. V. Vira,
  • I. I. Cherkes,
  • V. M. Palyukh,
  • M. V. Danylchuk

摘要

Improved mechanical properties of alumina (Al2O3) and alumina based ceramics are required due to the widespread application of these materials for high-temperature and wear-resistant components of critical equipment in aircraft, power generation, dentistry, and other industries. The purpose of this work was to evaluate the impact of the phase composition of the alumina based ceramics sintered with adding small amounts of sintering aids on resulting mechanical properties. The initial Al2O3 powder was mixed with various additives (MgO, K2O, CaO, CrO2, Fe2O3, PdO, La2O3) to improve its sintering ability and provide high mechanical and functional characteristics of sintered ceramics. The samples were sintered in a nitrogen atmosphere. The sintering temperature was set to 1850 °C while the isothermal holding time was set to 1–2 h. The microstructure and phase composition analyses, as well as the study of mechanical properties of ceramic samples, were carried out. Namely, the Vickers indentation and flexure tests were performed and values of microhardness, fracture toughness, and flexural strength of ceramics were estimated. All the material variants consisted of α-Al2O3 as the dominant phase and small amounts of secondary phases. In the sintering process, the phase of CaAl12O19 type was formed along with the dominant α-Al2O3 phase when adding small amounts of CaO, MgO, PdO, and/or other oxide nanopowders to the initial Al2O3 powder. Finally, a fine-grained ceramic microstructure was obtained. The optimum combination of strength, microhardness, and fracture toughness providing high reliability of alumina based ceramics was found for ceramic samples containing the matrix α-Al2O3 phase and the minor phase of CaAl12O19 type.