Atomic scale understanding of the TRIP-assisted dual-phase high-entropy alloys
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 to obtain the related information at atomic resolution.
The displacive phase transformation from face-centered cubic (FCC) γ phase to hexagonal close-packed (HCP) ε martensite and the reverse transformation (ε→γ) play a key role in enhancing the mechanical properties of FCC alloys, especially for the recently developed TRIP-assisted dual-phase HEAs. These phase transformations strongly depend on the stacking fault energy, instant temperature and stress condition during mechanical loading.
Within the statistical limits of TEM and energy dispersive spectroscopy (EDS), no indication for solute segregation and precipitation were found at interface between FCC γ and HCP ɛ phase in the dual-phase HEA. In the deformed samples, a mixed sub-structure consisting of γ nano-lamellas and twins was observed in HCP ɛ block. We also investigated the local displacive phase transformation at annealing twin boundaries in the dual-phase HEA. A systematic study is being carried out to understand the atomic structure of such annealing twin boundaries and the corresponding effect on phase transformation process.
International researcher team presents a novel microstructure design strategy for lean medium-manganese steels with optimized properties in the journal Science
In order to explore the possibility of using high entropy alloys (HEAs) for functional applications such as magnetic refrigeration it is necessary to have an in-depth understanding of their magnetic properties. The main goal of this project is to understand and improve the magnetic properties (e.g., saturation magnetization, Curie temperature etc.) in different medium and HEAs.
The goal of this project is to optimize the orientation mapping technique using four-dimensional scanning transmission electron microscopy (4D STEM) in conjunction with precession electron diffraction (PED). The development of complementary metal oxide semiconductor (CMOS)-based cameras has revolutionized the capabilities in data acquisition due to…