The diffusion kinetics of the BCC-structured high-entropy alloys (HEAs) is studied experimentally for the first time. First

the literature data regarding the transition-metal based

single-phase

BCC-structured HEAs is re-evaluated using the state-of-the-art

HEAs-dedicated TCHEA4 thermodynamic database

signalizing the need for further reassessment of the literature data accumulated during the last decade. The selected Al-Cr-Fe-Mn-V system was used for the interdiffusion experiments. The concentration profiles were evaluated using the numerical combinatorial approach

revealing surprisingly fast diffusion kinetics. The comparison with the available diffusion data for conventional BCC alloys supports recent findings regarding the lack of the ‘sluggish diffusion’ in HEAs.

IMPACT STATEMENT

The first-ever experimental study of interdiffusion in BCC-structured high-entropy alloys is conducted

revealing fast diffusion kinetics and providing a further argument against the presence of sluggish diffusion effect in HEAs.