Nanostructured metallic glasses : structure, properties and applications
Löffler, Jörg F.
FacultiesFakultät für Ingenieurwissenschaften, Informatik und Psychologie
InstitutionsInstitut für Funktionelle Nanosysteme
Metallic glasses are defined as amorphous metallic alloys since they combine the disordered atomic structure of traditional glasses with metallic interatomic bounding. As a result, they possess unique mechanical, magnetic and physical properties which makes them highly interesting for several applications. However, the lack of structural heterogeneities presents some drawbacks, since it is difficult to tailor the properties of this material in comparison to traditional polycrystalline metals. Furthermore, the plasticity of metallic glasses is rather limited and most of the time localized in one single shear band, which is a severe drawback for most applications. The aim of this doctoral thesis was to introduce structural heterogeneities at the nanoscale in metallic glasses in order to improve their plasticity and tailor their physical properties. These heterogeneities have been introduced by severe plastic deformation in bulk samples and by controlling the sputtering conditions in thin films. It was shown that severe plastic deformation modifies the plastic behaviour of the material, leading to a less serrated flow during nanoindentation. The growth modes responsible for the different thin film microstructures could be well understood. It was also demonstrated that nanoporous gold can be obtained by dealloying thin film metallic glass with the proper initial microstructure. Due to their high specific area and Au content, these dealloyed thin films are of high interest for applications such as catalyzers or surface-enhanced Raman spectroscopy.
VITRIMETTECH / Vitrified Metals Technologies and Applications in Devices and Chemistry / EC / FP7 / 607080
Subject HeadingsMetallisches Glas [GND]
Metallic glasses [LCSH]
High pressure physics [LCSH]
Sputtering (Physics) [LCSH]