Thermophysical properties of non-Zr-based multicomponent bulk metallic glass alloys

• Applicant: Professorin Dr. Isabella Gallino, Ph.D.
• Subject Area: Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials
• Term: from 2012 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 214287390

The present project deals with the thermophysical properties of known non-Zr-based bulk metallic glass (BMG) formers. The selected BMG systems are based on noble metals, on Mg, and two newly developed systems: the Ni-Cr-Nb-P-B system, and the steel system: Fe-Mo-Ni-Cr-P-C-B. The latter two BMG systems are not only of scientific interest but are also expected of great practical importance. The project goal is to identify to what extent the glass forming ability and the fragility of the undercooled liquid is influenced by the thermodynamics, and in particular: how much does the fragility correlate with the activation energy for cooperative atomic rearrangements in the supercooled liquid? How does this compare with the activation energies for diffusion? Is there any indication of a strong-to-fragile transition in these alloys? To what extent do nucleation-controlled crystallization processes dominate at high temperatures, in comparison with growth-controlled processes? How does annealing, or aging, near the glass transition temperature affect viscous flow and crystallization?The investigations will employ an ensemble of experimental techniques including differential scanning calorimetry (DSC/MDSC), dynamic mechanical analysis (DMA), dilatometry (TMA), x-ray photon correlation spectroscopy (XPCS), and in-situ high-intensity synchrotron X-ray scattering. Combined with the previous results, this will enable a comprehensive description of the thermodynamic, kinetic, and structural aspects for this class of non-equilibrium condensed matter and aim to gain new insights into the glass forming nature of BMG forming systems in general.

• DFG Programme: Research Grants