Regensburg 2019 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 12: Poster session I

MM 12.28: Poster

Monday, April 1, 2019, 19:15–20:45, Poster C

Impact of Severe Plastic Deformation on Al_xCoCrFeNi High Entropy Alloys — •Lena Frommeyer¹, Mehdi Eizadjou², Anna Ceguerra², Peter K. Liaw³, Harald Rösner¹, Sergiy Divinski¹, Simon Ringer², and Gerhard Wilde¹ — ¹Institute of Materials Physics, University of Münster, Münster, Germany — ²Australian Center for Microscopy and Microanalysis, University of Sydney, Australia — ³Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996, USA

During the last few years, a new class of materials called high entropy alloys has been extensively studied. The multi-principal element approach opens a wide compositional space with complex possibilities of combining 5 or more elements, each of them having originally equi-atomic concentration. The main research focus was initially set to obtain single-phase alloys. However, secondary phases in alloys can lead to improved properties. In this study, the high entropy alloy AlCoCrFeNi was modified by adding Al in various amounts. Moreover, the arc melted and homogenized alloys have been severely deformed by high pressure torsion (HPT). Subsequently, the un-deformed as well as the severely deformed alloys were examined by X-ray diffraction, electron back-scatter diffraction/transmission Kikuchi diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy and atom probe tomography. Transitions from pure fcc to fcc+B2 and to fcc+B2+A2 as well as severe grain refinement and high twin densities were observed and are discussed with respect to the variations of composition and strain.