Properties of Hot Compressed 21R SiAlON Ceramics with a Samarium Oxide Additive

Autor: S. N. Ivicheva, D. D. Titov, M. G. Frolova, K. A. Kim, Yu. F. Kargin, A. S. Lysenkov, D. V. Gridin, M. D. Mel’nikov, N. V. Petrakova
Rok vydání: 2021
Předmět:
Zdroj: Russian Journal of Inorganic Chemistry. 66:1196-1202
ISSN: 1531-8613
0036-0236
Popis: The compaction of initial powders, the bending strength, and the microhardness of 21R sialon ceramics obtained by hot pressing have been studied experimentally. It is found that the Sm2O3 sintering additive substantially reduces the annealing temperature and enhances the properties of the ceramics. The samples of 21R sialon ceramics without additives, which are prepared by annealing at 1950°C, have a density of 3.01 g/cm3, a bending strength of 240 ± 15 MPa, and a Vickers microhardness of 16.2 ± 0.4 GPa; the samples of 21R sialon ceramics with 2.5 wt % Sm2O3, which are annealed at 1750°C, are characterized by a density of 3.39 g/cm3, a bending strength of 315 ± 16 MPa, and a Vickers microhardness of 21.9 ± 0.2 GPa. It is shown that Sm2O3 reacts with 21R sialon in the temperature range of 1600–1700°C to form the 27R sialon and SmAlO3 impurity phases. In the samples annealed at 1750°C, the 27R sialon and Sm–sialon (Sm3Si2.5Al3.5O12.5N1.5) impurity phases are detected.
Databáze: OpenAIRE
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