Berlin 2015 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 28: Poster Session II

MM 28.23: Poster

Tuesday, March 17, 2015, 18:30–20:30, Poster E

Atomistic simulations of interfaces and dislocations in Mg-Al alloys — •Tobias Klöffel^1,2, Bernd Meyer², and Erik Bitzek¹ — ¹Materials Science and Engineering, Institute I, FAU Erlangen-Nürnberg — ²Interdisciplinary Center for Molecular Materials and Computer-Chemistry-Center, FAU Erlangen-Nürnberg

Their low density and high strength make magnesium alloys key structural materials for lightweight constructions. The intermetallic Mg₁₇Al₁₂ phase is the dominant precipitate phase and influences to a large degree the mechanical properties of Mg alloys. Here we present a computational study of Mg/Mg₁₇Al₁₂ interphase boundaries (IPBs), combining density functional theory (DFT) calculations with large-scale atomistic simulations using a semi-empirical potential of the modified embedded atom method (MEAM) type. DFT calculations of the γ surfaces in Mg₁₇Al₁₂ are used to validate the MEAM potential. DFT and atomistic calculations were then performed to characterize the IPB structure and energy for different orientation relationships to the Mg matrix. The results are compared to both, theoretical and experimental findings. Additional atomistic simulations were performed to determine the core structure and Peierls stress of various dislocations in the Mg₁₇Al₁₂ phase.