Microstructure and Stability of Metallic Nanoglasses

• Applicants: Professor Dr. Karsten Albe; Professor Dr.-Ing. Horst Hahn
• Subject Area: Mechanical Properties of Metallic Materials and their Microstructural Origins ; Glass, Ceramics and Derived Composites ; Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials
• Term: from 2006 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 30799144

Metallic nanoglasses are dense glasses with a significantly increased excess volume. They can be synthesized by consolidating amorphous metallic nanoparticles and exhibit a property profile that is clearly different from a melt spun bulk glass of the same composition. By means of molecular dynamics simulations of binary model glasses (Cu-Zr) we could show that glass-glass interfaces are characterized by a modified local order and an excess volume similar to that found in shear bands induced by plastic deformation. Experimentally studied Fe-Sc glasses exhibit clearly modified mechanical and magnetic properties and show a nanosized structural elements in the microstructure. It is the main goal of this research project to gain a consistent picture of the microstructural features of nanoglasses. Our primary scientific objective is to understand the physical origin of the massive density fluctuations that are observed experimentally and to find reasons for the unexpected thermal stability of nanoglasses.. In particular, we will study the sintering mechanisms occurring during cold compaction by varying particle sizes, pressures and materials. Experimentally, we will extend our study by non-magnetic Pd-Si, which can also be described by classical molecular dynamics simulations, while electronic structure calculations of Fe-Sc in bicrystal geometry shall assist in quantifying the experimental findings.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Herbert Gleiter