Strength can be controlled by edge dislocations in refractory high-entropy alloys
Journal
Nature Communications
Journal Volume
12
Journal Issue
1
Date Issued
2021
Author(s)
Lee C.; Chou Y.-C.
Abstract
Energy efficiency is motivating the search for new high-temperature (high-T) metals. Some new body-centered-cubic (BCC) random multicomponent “high-entropy alloys (HEAs)” based on refractory elements (Cr-Mo-Nb-Ta-V-W-Hf-Ti-Zr) possess exceptional strengths at high temperatures but the physical origins of this outstanding behavior are not known. Here we show, using integrated in-situ neutron-diffraction (ND), high-resolution transmission electron microscopy (HRTEM), and recent theory, that the high strength and strength retention of a NbTaTiV alloy and a high-strength/low-density CrMoNbV alloy are attributable to edge dislocations. This finding is surprising because plastic flows in BCC elemental metals and dilute alloys are generally controlled by screw dislocations. We use the insight and theory to perform a computationally-guided search over 107 BCC HEAs and identify over 106 possible ultra-strong high-T alloy compositions for future exploration. © 2021, The Author(s).
Subjects
alloy; alloy; entropy; strength; transmission electron microscopy; anisotropy; Article; chemical composition; controlled study; density functional theory; entropy; high resolution transmission electron microscopy; high temperature; mechanical test; neutron diffraction; scanning transmission electron microscopy; stereoradiography; transmission electron microscopy
SDGs
Publisher
Nature Research
Type
journal article