Metastable intermetallic phase precipitation from supersaturated Co solid solution and the consequences on microstructure evolution
The precipitation of intermetallic phases from a supersaturated Co(Nb) solid solution is studied in a cooperation with the Hokkaido University of Science, Sapporo.
These investigations show that the formation of metastable, coherent L12 NbCo3 strongly affects the microstructural evolution and growth of the equilibrium phase Nb2Co7. While these metastable fine L12 precipitates always form on directly cooling from the single-phase solid solution range to room temperature, their clearly visible formation reaction can be circumvented by an intermediate annealing step below the solvus temperature. This annealing results in a Widmannstätten-type microstructure with fine plates of the equilibrium Nb2Co7 phase in a Co matrix as shown in Fig. 1.
International researcher team presents a novel microstructure design strategy for lean medium-manganese steels with optimized properties in the journal Science
The aim of this project is to develop novel nanostructured Fe-Co-Ti-X (X = Si, Ge, Sn) compositionally complex alloys (CCAs) with adjustable magnetic properties by tailoring microstructure and phase constituents through compositional and process tuning. The key aspect of this work is to build a fundamental understanding of the correlation between…
In this project, we aim to achieve an atomic scale understanding about the structure and phase transformation process in the dual-phase high-entropy alloys (HEAs) with transformation induced plasticity (TRIP) effect. Aberration-corrected scanning transmission electron microscopy (TEM) techniques are being applied ...
Grain boundaries are one of the most important constituents of a polycrystalline material and play a crucial role in dictating the properties of a bulk material in service or under processing conditions. Bulk properties of a material like fatigue strength, corrosion, liquid metal embrittlement, and others strongly depend on grain boundary…
Grain boundaries are one of the most prominent defects in engineering materials separating different crystallites, which determine their strength, corrosion resistance and failure. Typically, these interfaces are regarded as quasi two-dimensional defects and controlling their properties remains one of the most challenging tasks in materials…
Project A02 of the SFB1394 studies dislocations in crystallographic complex phases and investigates the effect of segregation on the structure and properties of defects in the Mg-Al-Ca System.
Within this project, we will investigate the micromechanical properties of STO materials with low and higher content of dislocations at a wide range of strain rates (0.001/s-1000/s). Oxide ceramics have increasing importance as superconductors and their dislocation-based electrical functionalities that will affect these electrical properties. Hence…