Research on high specific strength as-cast AlxNbTiVZr high entropy alloys

Abstract

The effect of continuously varying aluminium with a low content ( x = 0.1–0.5) on as-cast AlxNbTiVZr high entropy alloys (HEAs) was studied. AlxNbTiVZr ( x = 0.1, 0.2) HEAs showed a single BCC phase, while some lamellar second phases precipitated along the grain boundaries in AlxNbTiVZr ( x = 0.3, 0.4, 0.5) alloys. With the increase in Al percentage, the compressive strength of AlxNbTiVZr HEAs increased from 1452 to 1667 MPa, whereas their ductility decreased from 19.40 to 6.15%. Notably, the AlxNbTiVZr HEAs showed both a higher specific yielding strength and considerable plastic strain than other Nb-Ti-V-X-Y HEAs and commercial Mg-, Ti-, and Ni-based alloys. Finally, the fracture morphologies of AlxNbTiVZr ( x = 0.1–0.2) HEAs showed some features of compression ductility.