The goal of our group is to develop novel high-entropy alloys (HEAs) with exceptional mechanical, physical and chemical properties based on the understanding of their structure-properties relations. This is being achieved by using the advanced experimental techniques and the state-of-the-art theoretical methods.
Conventional alloy design over the past centuries has been constrained by the concept of one or two prevalent base elements. As a breakthrough of this restriction, the concept of HEAs opens a new realm of numerous opportunities for investigations in the huge unexplored compositional space of multi-component alloys.
As a typical example shown in Figure 1, while conventional alloys use strengthening mechanisms such as grain boundaries, dual-phase structure, dislocation interactions, precipitates and solid solution (e.g. steels, Ti-alloys, Al-alloys), our recently developed novel interstitial TWIP-TRIP-HEAs concept combines all available strengthening effects, namely, interstitial and substitutional solid solution, TWIP, TRIP, multiple phases, precipitates, dislocations, stacking faults and grain boundaries. This leads to the exceptional strength-ductility combination of the novel HEAs, exceeding that of most metallic materials.
Our research group (High-Entropy Alloys) conducts the state-of-the-art research work employing novel experimental-theoretical methodologies (e.g., EBSD, ECCI, FIB-APT, TEM, Calphad and DFT; Figure 2) in the following specific aspects:
Excellent strength-ductility combination of transitional metal HEAs;
Resistances to hydrogen-embrittlement and corrosion of HEAs
Light-weight high-strength HEAs
High-temperature refractory high-strength HEAs
Multifunction of HEAs
Defects, segregations and thermodynamics in HEAs
In-situ observation of deformations in HEAs under electron microscopes
These aspects are strongly interconnected and facilitate an extensive collaboration network with national and international experts.
Rao, Z.; Springer, H.; Ponge, D.; Li, Z.: Combinatorial development of multicomponent Invar alloys via rapid alloy prototyping. Materialia 21, 101326 (2022)
Guo, Y.; He, J.; Li, Z.; Jia, L.; Wu, X.; Liu , C.: Strengthening and dynamic recrystallization mediated by Si-alloying in a refractory high entropy alloy. Materials Science and Engineering A: Structural Materials Properties Microstructure and Processing 832, 142480 (2022)
Guo, Y.; Jia, L.; He, J.; Zhang, S.; Li, Z.; Zhang, H.: Interplay between eutectic and dendritic growths dominated by Si content for Nb–Si–Ti alloys via rapid solidification. Journal of Manufacturing Science and Engineering, Transactions of the ASME 144 (6), 061007 (2022)