Berlin 2015 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 8: Liquid and Amorphous Metals II: Structure Formation in Metallic Glasses

MM 8.5: Vortrag

Montag, 16. März 2015, 12:45–13:00, H 0107

Influence of micro alloying on the bulk metallic glass former PdNiP — •Niklas Nollmann, Isabelle Binkowski, Harald Rösner, and Gerhard Wilde — Westfälische Wilhelms-Universität, Münster

When describing the deformation of bulk metallic glasses (BMGs), two different modes have to be distinguished. For high temperatures and low stresses homogeneous flow occurs, whereas for low temperatures and high stresses the flow becomes inhomogeneous. During inhomogeneous deformation of metallic glasses (e.g. in compression or bending) the strain is localized in thin regions, the so-called shear bands. In general, bulk metallic glasses show almost no ductility during plastic deformation. For instance, in compression tests BMGs fail catastrophically mostly at the location of one shear band that is typically inclined at about 45 degrees with respect to the load axis. The investigated PdNiP glass features a high ductility in bending compared to different metallic glasses. By the use of micro alloying, the mechanical properties of metallic glasses can be influenced. In our investigation, we demonstrate that the ductility in bending and compression of the PdNiP bulk metallic glass can be altered by adding small amounts of a differing element. Whereas cobalt additions improve the ability of plastic deformation, an iron addition leads to an almost complete loss of ductility. The results are discussed concerning the possible interrelation between minor alloying and plasticity enhancement.