Berlin 2015 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 33: Structural Materials I: Phase Stability and Mechanical Properties

MM 33.1: Talk

Wednesday, March 18, 2015, 10:15–10:30, TC 010

Comparison of Co-X and Ni-X systems with density functional theory and bond-order potentials — •Jörg Koßmann, Alvin Ladines, Thomas Hammerschmidt, and Ralf Drautz — ICAMS, Ruhr-Universität Bochum, Germany

Single crystal superalloys are used widely in high-temperature applications. Most of todays superalloys are based on Ni-Al and comprise 10 or more alloying elements. For example, Re and other 5d elements are added to improve creep resistance. Recently, materials based on Co-Al-W where shown to possess a γ/γ^′ microstrcuture which makes these alloys interesting for singe crystal superalloy applications. We compare and contrast Co-based and Ni-based alloys from high-throughput density-functional theory (DFT) calculations. We relate phase stabilities, lattice constants, and elastic constants in Co-X and Ni-X binaries with X=Al,W,Re and the ternary systems Co-Al-W and Ni-Al-Re. New bond-order potentials (BOPs) are fitted to the DFT results and we obtain satisfactory agreement between BOP and DFT.