Deformation behavior of metallic glasses - Elastic deformation, Plastic deformation and fracture

Datum

22.04.2016

Zeit

11:00 - 12:00

Sprecher

Prof. Gang Wang

Zugehörigkeit

Shanghai University, Laboratory for Microstructures, China

Sprache

en

Hauptthema

Materialien

Andere Themen

Materialien, Physik

Host

Brit Präßler-Wüstling

Beschreibung

Tremendous research effort has been put to the study of deformation mechanisms of metallic glasses (MGs), attempting to elucidate the origin of their high fracture strength. Yet, the deformation mechanism of MGs is still unclear. In this talk, we will introduce that a series of MGs with different yield strengths are studied with a focus on the fine structural evolution (at the atomic level) during their elastic deformation regime. A concordant region is formed as a result. The relation between this concordant region and the yield strength is thoroughly discussed in terms of its size and the stress level in this region. In the plastic regime, the serrated flow behavior will be statistically analyzed. The dynamic behavior of plastic deformation will be discussed based on the chaotic and self-organized critical states observation. The influences temperature and the second crystalline phase on the serrated flow behavior of MGs are investigated to explore the method to enhance the plastic deformation behavior of MGs. In the fracture stage, the elastic energy accumulated in the elastic deformation regime will be released to cause the fracture of MGs. Depending on MGs’ fracture toughness, the failure mode can be dominated by shear-banding failure (for tough MGs) or cracking failure (for brittle MGs). Through quantitatively evaluating the balance between the fracture energy and the elastic energy, the failure modes are discussed based on a hyperelasticity model. KEYWORDS: Elastic deformation, yield strength, metallic glasses, structural evolution, concordant region

Links

• Seminars at the IFW

Letztmalig verändert: 22.04.2016, 09:56:03