Berlin 2018 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 46: Liquid and Amorphous Metals

MM 46.1: Talk

Wednesday, March 14, 2018, 17:00–17:15, TC 010

Analysis of a severely deformed Pd₄₀Ni₄₀P₂₀ bulk metallic glass — •Afrouz Hassanpour, Sergiy Divinski, Martin Peterlechner, and Gerhard Wilde — Institute of Materials Physics, Westfälische Welhilms-Universität Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany

For practical usage of bulk metallic glasses (BMG) it is crucial to enhance material properties, such as tensile and compression ductility and fracture toughness. In the present work, Pd₄₀Ni₄₀P₂₀ bulk metallic glass was analyzed to study its behavior under conditions of severe deformation via high-pressure torsion (HPT). Amorphous samples were produced by copper mold casting in a melt spinner under argon atmosphere. X-ray diffraction, differential scanning calorimetry (DSC), and Transmission Electron Microscopy (TEM) were performed. The degree of deformation was systematically varied by applying different numbers of rotation with HPT from 0 (just compression) to 10 turns. HPT causes significant changes of the thermo-mechanical properties. It turned out, that unlike after deformation by cold-rolling, HPT deformation at room temperature induced a nanocrystallization transformation in the deeply undercooled liquid above the glass transition. Also structural relaxation by annealing and its impact on the nanocrystallization at higher temperatures was experimentally investigated for as-cast and HPT-processed states. The results are discussed in conjunction with dedicated TEM investigations for annealed and as-deformed amorphous samples.