Liquid-metal-mediated low-temperature sintering synthesis of high-entropy alloys with on-demand composition and performance

Significant research attention has focused on high-entropy alloys (HEAs) due to their distinctive chemical cooperativity and crystallographic strain phenomena. Nevertheless, combining constituents exhibiting substantial atomic radius mismatches promotes pronounced compositional partitioning during fabrication. HEAs require 1,800°C processing for entropy stabilization, causing volatile-element loss. Here, our Ga-mediated approach enables functionalized Ga-based HEA (GHEAs) fabrication at 600°C. The cooperative interaction of Ga's negative mixing enthalpy and increased configurational entropy reduces Gibbs free energy, facilitating bulk GHEA formation during low-temperature sintering. Thermodynamic analysis, density functional theory computations, and elemental analysis verify this Ga-alloying mechanism. Functionalized phase selection (face-centered cubic [FCC] and body-centered cubic [BCC]) is tunable through atomic size and valence electron concentration adjustments. FCC electrocatalytic GHEAs show exceptional oxygen evolution reaction activity in 1 M potassium hydroxide (KOH). Similarly, BCC refractory and FCC soft magnetic GHEAs exhibit significant promise for aerospace components and electronic devices. Hence, this methodology establishes a versatile design framework for application-specific GHEAs.