Regensburg 2016 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 35: Structural Materials II

MM 35.3: Vortrag

Mittwoch, 9. März 2016, 12:15–12:30, H52

Structure of the high entropy alloy Al_xCrFeCoNi: fcc versus bcc — •Masako Ogura¹, Tetsuya Fukushima², Rudolf Zeller¹, and Peter H. Dederichs¹ — ¹Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, Jülich, Germany — ²Graduate School of Engineering Science, Osaka University, Toyonaka, Japan

High entropy alloys (HEAs) are disordered multi-component systems with equal or near-equal atomic ratios. They have simple solid solution structures, e.g., bcc and fcc structures, stabilized by the high disorder entropy effect. The structure of HEAs with Al such as Al_xCrFeCoNi and Al_xCrFeCoNiCu changes from fcc to bcc with increasing the Al concentration. In this study, we investigate the effect of Al on the structure of the HEA Al_xCrFeCoNi on the basis of first-principles electronic structure calculations. The calculations are performed with the KKR Green’s function method in the framework of the density functional theory using GGA. The disordered alloys are simulated by the coherent potential approximation or supercell calculations with several hundred atoms. We discuss the change from fcc to bcc structures and the importance and stability of partially disordered B2 and L1₂ structures.