Speaker
Description
High entropy alloys (HEA) are a new class of metallic alloys with more than four
approximately equimolar elements and are promising structural materials with partially
outstanding mechanical properties. To understand the mechanical behaviour of
HEAs it is essential to investigate their intrinsic dislocation deformation
mechanism and the associated kinetic signatures.
Experimental results as well as theoretic calculations indicate chemical sublattice ordering
(SLO) in HEAs at low temperature and sufficient time to be kinetically accessible during
synthesis. The impact of SLO on different HEAs is evaluated by density functional theory
(DFT). The respective implication on possible slip systems, which are crucial to describe the
deformation mechanism, are predicted by dislocation theory with different levels of
approximations. DFT is used to determine the needed material parameters to assess the
elastic properties, the energetics of SLO and the generalized stacking fault energies.
