Metals and alloys are one of the most important material classes in today’s society and the exploration of novel pathways for harnessing microstructure-property relationships is one of the major drivers for current research. Microstructure tuning at the nanoscale becomes crucial in cases where the system size is on the order of microns or smaller, e.g. in thin films.
We develop novel microstructure design tools, such as pulsed metallurgy, to create thin film composites by phase transformations induced by thermal pulsing.
Our research is motivated by the fabrication materials with optimized strength and deformability and focuses on metallic multilayers as prototype materials. In these materials, we harness early-stage phase precipitation under rapid heating with rates up to 106 K/s for embedding intermetallic compounds in a metallic thin film matrix. The periodically stacked microstructure of the multilayers serves for us as template that affects how intermetallic compounds precipitate. However, it is not clear what protocol to use to limit the precipitation to the nanometer scale, to adjust the desired precipitate shape and crystal structure. Pulsed metallurgy encompasses both the development as well as methods for the application of pre-defined thermal protocols enabling us to control and link the thin film microstructure to its properties and performance.
Our expertise includes
- Interdiffusion and grain boundary diffusion in nanoscale materials
- Phase transformation under accelerated heating protocols
- Thermal analysis of phase transformations in thin films using thin film resistive heaters and nanocalorimetry
- Complementary in situ thermal-structural analysis of phase transformations using combined nanocalorimetry and time-resolved-synchrotron X-ray diffraction
- Thin film structure and chemistry characterization via electron microscopy (SEM, STEM and TEM)