Thermal-electric coupled sintering-induced grain refinement and mechanical enhancement of binder jetting Al₀.₅Cr₀.₉FeNi₂.₅V₀.₂ high-entropy alloy

A thermal-electric coupled sintering (TECS) strategy was applied to binder-jetted Al₀.₅Cr₀.₉FeNi₂.₅V_0.2 high-entropy alloy (HEA) green parts to tailor microstructure and mechanical properties. The effects of sintering temperature and direct current on densification, phase constitution, elemental segregation, and tensile behavior were investigated. The applied current had limited influence on overall densification and did not alter the primary FCC/L1₂ phase constitution. However, sintering with a 5 A current effectively suppressed grain coarsening, reducing the average grain size from 58.7 μm to 20.4 μm at 1330 °C and from 107.9 μm to 60.8 μm at 1340 °C. At 1340 °C, the 5 A current also reduced the average diameter of the L1₂ precipitates from 55.6 to 43.6 nm and increased their volume fraction from 25.6% to 32.7%. Meanwhile, the initially continuous Cr/V-rich grain-boundary segregation was divided into discontinuous segments. Under the 1340 °C + 5 A condition, the alloy achieved a yield strength (YS) of 709 MPa, an ultimate tensile strength (UTS) of 848 MPa, and a uniform elongation (UE) of 8.8%, representing increases of 9.2%, 14.1%, and 60.0%, respectively, compared with the current-free sample. The enhanced strength–ductility synergy is attributed to the combined effects of grain refinement, L1₂ precipitate refinement, and grain-boundary segregation reconstruction. © 2026 The Authors.