Microstructure, mechanical properties, and thermal stability of γ-Nb5Si3 under high temperature and high pressure

The study of the effect of pressure and temperature on the structural and mechanical properties of materials is very difficult for current experimental techniques. Here, we have synthesized the γ-Nb5Si3 compound with remarkable quality by high pressure and high temperature (HPHT) technology. The effects of high pressure and sintering temperature on its microstructure, mechanical properties, and oxidation resistance are discussed. The Vickers hardness and density of the γ-Nb5Si3 sample at 5.5 GPa and 1100 °C are 8.67 GPa and 5.73 g/cm3, respectively. It is shown that the HPHT behavior not only improves sample's compactness and microstructure, but also makes γ-Nb5Si3 to have a strong response to the Vickers hardness and related density. These results effectively demonstrate the functions of the HPHT technology, which accurately express the Vickers hardness, density, and thermal stability of γ-Nb5Si3 compounds.