| Autor: |
Nikonova, R. M., Larionova, N. S., Lad'yanov, V. I. |
| Zdroj: |
Journal of Surface Investigation: X-Ray, Synchrotron & Neutron Techniques; Feb2024, Vol. 18 Issue 1, p235-240, 6p |
| Abstrakt: |
The results of studying a composite material based on Nb–Si–C are presented. The alloy was obtained by aluminothermic self-propagating high-temperature synthesis. To prepare the initial charge a mixture of powders of commercial niobium pentoxide Nb2O5 and commercial silicon carbide SiC was used. The process of niobium oxide Nb2O5 reduction was implemented using an aluminum powder. The study of the Nb–Si–C ternary system is of interest in terms of obtaining high-temperature materials of new generation for gas turbine engine construction capable of replacing heat-resistant nickel alloys, as well as the potential possibility of forming MAX phases (Mn + 1AXn phases, where n = 1, 2, 3, ... ; M is the transition d-metal; A is the p-element; and X is carbon). The phase composition of the obtained Nb–Si–C composite was studied by X-ray diffraction. It has been shown that as a result of high-temperature synthesis NbC carbide and γ-Nb5Si3 and NbSi2 silicides are formed which are competing relative to the Nb2SiC MAX phase. The formation of Nb2SiC under the selected synthesis conditions was not detected. Using scanning electron microscopy and X-ray spectral analysis, the morphological distribution of the phases formed during high-temperature synthesis is analyzed in detail. It is shown that NbC carbide makes up the majority of the volume of the composite and is present in the form of pyramidal-shaped particles with a pyramid face size of ~10 μm. NbSi2 silicides are elongated rod-shaped particles with smooth edges measuring 30 × 80 μm; Nb5Si3 silicides do not have a specific shape. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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