Berlin 2018 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 58: Liquid and Amorphous Metals

MM 58.2: Vortrag

Donnerstag, 15. März 2018, 12:00–12:15, TC 010

Novel atomic-level mechanism governing shear banding in metallic glasses — •Daniel Şopu^1,2, Alexander Stukowski¹, Mihai Stoica³, and Sergio Scudino⁴ — ¹Institut für Materialwissenschaft, Technische Universität Darmstadt, Otto-Berndt-Straße 3, D-64287 Darmstadt, Germany — ²ErichSchmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstrasse 12, A-8700 Leoben, Austria — ³ErichSchmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstrasse 12, A-8700 Leoben, Austria — ⁴IFW Dresden, Institut für Komplexe Materialien, Helmholtzstraße 20, D-01069 Dresden, Germany

The most conceivable scenario of shear band formation is the percolation of shear transformations zones (STZ) along a viable plane of maximum shear stress. However, despite the recent research progress, how an autocatalytic chain reaction of STZ takes place in a metallic glass remains a critical question that has not been resolved so far in the field. Here, by using molecular dynamics simulations, we provide a new atomic-level mechanism underlying the STZ percolation process. The mechanism is based on the autocatalytic generation of successive strong strain and rotation fields, leading to STZ percolation and, ultimately, to the formation of a shear band. The results build a bridge between the discrete nature of STZs at the atomic-level and the rather continuous character of shear bands at the microscale. We suggest that our results may have significant implications for understanding several aspects characterizing the process of shear banding in metallic glasses and other disordered materials.