Projekte
Completed projects
Creep behavior of advanced directionally solidified multi-phase Mo-alloys with and without coating (HTMA-DS Mo)
Duration: 01.03.2020 bis 31.01.2024
Mo-Hf-B and Mo-Zr-B alloys as a new class of refractory alloys are potential candidates in stationary and mobile turbine applications. Due to the high melting points of the constituents high-temperature strength and creep strength are expected up to 1,400 °C. Those high service temperatures, in turn, may result in higher turbine efficiencies and may reduce primary energy consumption.
As a manufacturing route, directional solidification via zone melting as a new processing approach for Mo-Hf-B and Mo-Zr-B results in low oxygen (< 50 ppm) impurities, which is essential to avoid embrittlement of these alloys; moreover the materials possess an anisotropic lamellae-reinforced microstructure.
Density functional theory calculations on metals and intermetallics
Duration: 01.10.2019 bis 30.09.2022
With the aid of density functional theory it is possible to adress many questions regarding metals and intermetallics likewise. Not only it is possible to predict the crystal structure of a solid, but also the ability to investigate and explain site preferences within intermetallics like borides and silicides comes in handy. It is also very important to determine the stability of metals and intermetallics and, in doing so, the electronic and phononic properties is investigated. The phase stability of matrix, side phases and precipitations depends on the temperature and the pressure and therefore one uses first principles calculations to investigate the thermodynamic properties of these metals and intermetallic phases at least qualitatively. The elastic properties of the metals and intermetallics can also be predicted to a very good precision.
Density functional theory is therefore the ideal ansatz to investigate metals and intermetallics as it is accurate and fast.
FlexiDS: Aufklärung der Phasen- und Mikrostrukturbildung während der gerichteten Erstarrung neuer metallischer und intermetallischer Materialien durch in-situ Beobachtung des Erstarrungsvorganges mit Photonenbeugung
Duration: 01.08.2016 bis 31.07.2019
Im Projekt FlexiDS soll in Kooperation mit dem Karlsruher Institut für Technologie (KIT) der Prozess der gerichteten Erstarrung in verschiedenen Hochtemperaturmaterialien mit in-situ Röntgenbeugung untersucht werden. In diesem Rahmen soll eine innovative in-situ Probenumgebung für gerichtete Erstarrung an der HEMS-Beamline (High Energy Material Science) des DESY (Deutschen Elektronen Synchrotron, Hamburg) entwickelt und aufgebaut werden. Diese wird den beteiligten Partnern völlig neue Forschungs- und Charakterisierungsmöglichkeiten durch direkte Beobachtung des gerichteten Erstarrungsprozesses bieten. Das Helmholtz-Zentrum-Geesthacht (HZG), das diese Beamline betreut, wird die Konzeption, den Bau und den Betrieb der Probenumgebung unterstützen.