An <i>in situ</i> ambient and cryogenic transmission electron microscopy study of the effects of temperature on dislocation behavior in CrCoNi-based high-entropy alloys with low stacking-fault energy

Temperature is known to affect deformation mechanisms in metallic alloys. As temperature decreases, the stacking-fault energy many face-centered cubic (fcc) alloys resulting a change of mode from dislocation slip twinning. Such an impact can be more complex compositionally heterogeneous microstructures that exhibit, for example, local concentration fluctuation such as multi-principal element In this work, we compare behavior and mechanical properties fcc Cr20Mn10Fe30Co30Ni10 high-entropy alloy at ambient liquid-nitrogen temperatures. We find network stacking faults formed by uniformly extended dislocations temperatures with low energy, whereas lower temperatures, uneven dissociation becomes significant, which results severe pile-ups together their pronounced entanglement. Our findings indicate decreases decreasing temperature, heterogeneity distribution elements dominant tuning variation lattice resistance. result, strongly affects microstructural evolution consequently leads significantly work hardening.