AlNbTiVZr refractory high entropy alloy combining exceptional high-temperature performance and excellent ductility fabricated by laser direct energy deposition.

In this study, a new refractory high entropy alloy (RHEA) AlNbTiVZr is fabricated by laser direct energy deposition (LDED), and an investigation is conducted to explore the hot deformation. The body-centered cubic (BCC) phase structure and a small number of close-packed hexagonal Laves intermetallic phases of RHEA are predicted by combining XRD with the calculation of empirical parameters. Compression tests are carried out at different temperatures, and the results show that no fracture occurs when the strain reaches 50% at any of the temperatures tested while exhibiting a high yield stress. The dynamic softening effect is enhanced as the temperature increases and the yield stress decreases significantly. A slight hardening trend is observed during the steady-state flow stage of the stress-strain curve. The softening of RHEA is mainly caused by dynamic reversion (DRV) and assisted dynamic recrystallization (DRX), where the atomic mobility at the grain boundaries increases with temperature, promoting the creation of recrystallized grains. • LDED manufactured Al-Nb-Ti-V-Zr RHEA refractory high-entropy alloy with excellent ductility and strength. • Investigated the high-temperature deformation behavior of ALNBTI refractory high-entropy alloy. • Revealed the mechanisms of dynamic recrystallization and dynamic recovery under high-temperature conditions. [ABSTRACT FROM AUTHOR]