5 Werkstofftechnik
Filtern
Erscheinungsjahr
- 2022 (19) (entfernen)
Dokumenttyp
- Vortrag (10)
- Zeitschriftenartikel (5)
- Posterpräsentation (4)
Schlagworte
- Alkali zinc borate glasses (4)
- Glass (4)
- Oxidglas (4)
- Sintering (4)
- Bildanalyse (3)
- Crystallization (3)
- Digitaler Zwilling (3)
- ML (3)
- Ontologie (3)
- Bioactive Glass (2)
- Bond energy (2)
- Lead borate glasses (2)
- Material Digital (2)
- Raman spectroscopy (2)
- Robotische Glasschmelzanlage (2)
- Silver metallization paste (2)
- Surface energy (2)
- Viscosity (2)
- robotische Glasschmelzanlage (2)
- 3D printing (1)
- Batch reactions (1)
- Borate (1)
- Crystal lattice (1)
- Crystal orientation (1)
- Diffusion (1)
- Fluorescence spectroscopy (1)
- Foaming (1)
- Fracture surface (1)
- Fracture surface energy (1)
- Fracture toughness (1)
- Fragility (1)
- Gefüge (1)
- Glas (1)
- Glass forming melts (1)
- Glass manufacturing (1)
- Glass melt (1)
- Hot stage microscopy (1)
- IR spectroscopy (1)
- Nucleation mode (1)
- Nucleation tendency (1)
- Oriented surface crystallization (1)
- Oxide glass (1)
- Physical properties (1)
- Precipitation (1)
- Silber (1)
- Silver (1)
- Silver cluster (1)
- Silver diffusion (1)
- Sintern (1)
- Sodium zinc borate glass (1)
- Structure (1)
- Transmission electron microscopy (1)
- Young’s Modulus (1)
Organisationseinheit der BAM
- 5.6 Glas (19) (entfernen)
Eingeladener Vortrag
- nein (10)
Although the slow crack growth in glass is dominated by stress-corrosion phenomena, it also should reflect the underlaying intrinsic fracture behavior controlled by glass chemistry and structure. To investigate such underlaying phenomena, crack growth velocity in alkali silicate glasses was measured in vacuum across 10 orders of magnitude with double cantilever beam technique. Measured and literature crack growth data were compared with calculated intrinsic fracture toughness data obtained from Young’s moduli and theoretical fracture surface energy. Data analysis reveals slight correlation with the packing density and significant deviations from the intrinsic brittle fracture behavior. These deviations do not follow simple compositional trends. Two opposing processes may explain this finding: a decrease in the apparent fracture surface energy due to stress-induced chemical changes at the crack tip and its increase due to energy dissipation during fracture.
As part of a joint project involving the Fraunhofer Institute for Silicate Research (ISC), the Friedrich Schiller University of Jena, the Clausthal University of Technology and the Federal Institute for Materials Research and Testing (BAM), digital tools are to be created for the development of new types of glass materials. Current processes for the production of glasses with improved properties are usually very cost- and energy-intensive due to the low degree of automation and are subject to long development cycles. The use of robotic synthesis processes in combination with self-learning machines is intended to overcome these problems in the long term. The development of new types of glass can then not only be accelerated considerably, but also be achieved with much less effort.
In this talk, data generation via a robotic high-throughput glass melting system is presented, which should be the experimental basis for the ontology developed within the project GlasDigital.
We present an easy-to-apply method to predict structural trends in the internal nucleation tendency of oxide glasses. The approach is based on calculated crystal fracture surface energies derived from easily accessible diatomic bond energy and crystal lattice data. The applicability of the method is demonstrated on literature nucleation data for isochemically crystallizing oxide glasses.
Up to now, oriented surface crystallization phenomena are discussed controversially, and related studies are restricted to few glasses. For silicate glasses we found a good correlation between the calculated surface energy of crystal faces and oriented surface nucleation. Surface energies were estimated assuming that crystal surfaces resemble minimum energy crack paths along the given crystal plane. This concept was successfully applied by Rouxel in calculating fracture surface energies of glasses. Several oriented nucleation phenomena can be herby explained assuming that high energy crystal surfaces tend to be wetted by the melt. This would minimize the total interfacial energy of the nucleus. Furthermore, we will discuss the evolution of the microstructure and its effect on the preferred crystal orientation.
Up to now, oriented surface crystallization phenomena are discussed controversially, and related studies are restricted to few glasses. For silicate glasses we found a good correlation between the calculated surface energy of crystal faces and oriented surface nucleation. Surface energies were estimated assuming that crystal surfaces resemble minimum energy crack paths along the given crystal plane. This concept was successfully applied by Rouxel in calculating fracture surface energies of glasses. Several oriented nucleation phenomena can be herby explained assuming that high energy crystal surfaces tend to be wetted by the melt. This would minimize the total interfacial energy of the nucleus. Furthermore, we will discuss the evolution of the microstructure and its effect on the preferred crystal orientation.
Die technischen Möglichkeiten der robotischen Glasschmelzanlage der BAM werden vorgestellt.