| Résumé | This study investigates the micro/nanostructural features and mechanical responses of a novel TiAl/Ti3Al/Al2O3 cermet fabricated by self-propagation high-temperature synthesis. The microscopic diagnosis was used to examine the material composition, phase distribution, and elemental concentration of the cermet. Three phases were identified in the cermet, including γ-TiAl, α2-TiAl, and Al2O3. The material exhibited ultrafine microstructure with the size of alumina particles between 0.5 µm and 1.5 µm occupying 65 ± 1% areal fraction of the material. Transmission electron microscopy (TEM) was employed to examine the “coral” network of alumina particles with the titanium aluminide matrix, which was believed to be contributing to the failure of the material. Iron/nickel-based nano-precipitates were found through TEM as well, and these were believed to be contributing to the mechanical properties of the material. The rate-dependency on the compressive strength and failure mechanisms were studied by quasi-static and dynamic uniaxial compression, and it was found that the quasi-static and dynamic compressive strengths were 2400 ± 120 MPa and 3370 ± 450 MPa, respectively. The results are compared with those for alumina AD995 to highlight differences in mechanical properties, such as compressive strength and failure strains. These findings serve as the preliminary dataset for material design, manufacturing, and modeling of advanced cermets. |
|---|
