Nb-Al2O3 refractory composites are highly promising materials for use as carbon-free components in high-tech manufacturing. They exhibit low shrinkage behavior and good thermal resistance. With the development of new production techniques, it is expected that energy consumption can be minimized. Recently, fine- and coarse-grained niobium-alumina composites were developed using different manufacturing methods such as slip-casting and extrusion. In our research project, we study the high-temperature mechanical properties of these refractory niobium-alumina composites under compressive loads up to 1500°C.
After exposing these materials to high temperatures, additional phases such as tantalates (AlTaO4) and niobium oxides (NbO) were observed in the microstructure. Since these phases may significantly affect the mechanical properties of the bulk material, it is necessary to understand their mechanical behavior. However, to the best knowledge, no detailed information on the mechanical properties of tantalates and NbO can be found in the literature, yet. Therefore, we used nanoindentation to characterize the micromechanical behavior of these phases (AlTaO4 and NbO) at room temperature. We carried out several nanoindentation measurements on Ta, Nb, and Al2O3 grains, as well as on AlTaO4 and NbO phases.
Gökhan Günay graduated from Samsun Ondokuz Mayis University, Department of Materials Science and Engineering in 2013, and then joined Gebze Technical University in 2015. He has worked on several national research programs at TUBITAK MRC in Turkey. During his master's studies, he conducted research on the heat-treatment process parameters of Ni-based single crystal CMSX-4 superalloys, which he completed in 2017. Since November 2019, he has been working as a researcher and doing his PhD studies at TU Freiberg, conducting research on the high-temperature mechanical behavior of Ta/Nb-Al2O3 refractory composite materials.
Nb-Al2O3 refractory composites are highly promising materials for use as carbon-free components in high-tech manufacturing. They exhibit low shrinkage behavior and good thermal resistance. With the development of new production techniques, it is expected that energy consumption can be minimized. Recently, fine- and coarse-grained niobium-alumina composites were developed using different manufacturing methods such as slip-casting and extrusion. In our research project, we study the high-temperature mechanical properties of these refractory niobium-alumina composites under compressive loads up to 1500°C.
After exposing these materials to high temperatures, additional phases such as tantalates (AlTaO4) and niobium oxides (NbO) were observed in the microstructure. Since these phases may significantly affect the mechanical properties of the bulk material, it is necessary to understand their mechanical behavior. However, to the best knowledge, no detailed information on the mechanical properties of tantalates and NbO can be found in the literature, yet. Therefore, we used nanoindentation to characterize the micromechanical behavior of these phases (AlTaO4 and NbO) at room temperature. We carried out several nanoindentation measurements on Ta, Nb, and Al2O3 grains, as well as on AlTaO4 and NbO phases.
Gökhan Günay graduated from Samsun Ondokuz Mayis University, Department of Materials Science and Engineering in 2013, and then joined Gebze Technical University in 2015. He has worked on several national research programs at TUBITAK MRC in Turkey. During his master's studies, he conducted research on the heat-treatment process parameters of Ni-based single crystal CMSX-4 superalloys, which he completed in 2017. Since November 2019, he has been working as a researcher and doing his PhD studies at TU Freiberg, conducting research on the high-temperature mechanical behavior of Ta/Nb-Al2O3 refractory composite materials.
