A Ti‐Rich Corrosion‐Resistant Multiprincipal Element Alloy With Outstanding Mechanical Properties Over a Wide‐Temperature Range

Lightweight multiprincipal element alloys (MPEAs) have recently emerged as promising candidates owing to their low density and high specific yield strength; however, their limited tensile ductility impedes applicability in engineering fields. In this study, a novel Ti 72 Cr 12 Al 8 Nb 7 Mo 1 MPEA was synthesized using vacuum arc melting, homogenization, cold rolling, and recrystallization annealing. This Ti‐rich MPEA with a single BCC phase exhibits excellent mechanical properties, with a room‐temperature specific yield strength of ∼185 MPa·cm 3 /g and a tensile strain of ∼24.5%. High dislocation density and synergistic dislocation interactions enhance both deformability and strength. The dynamic Hall‐Petch effect induced by dislocation slip provides a sustained hardening rate, contributing to the outstanding tensile properties. At 700°C, the alloy shows a tensile yield strength of ∼250 MPa and a total elongation exceeding 50%. The softening mechanism is primarily attributed to dislocation cross‐slip/climb, annihilation, and dynamic recrystallization. In addition to its uniform phase composition and small grains, the outstanding corrosion resistance is attributed to the formation of Nb 2 O 5 in the passive film, which suppresses oxygen vacancies and chloride ion attack. Consequently, the exceptional mechanical properties and corrosion resistance of Ti 72 Cr 12 Al 8 Nb 7 Mo 1 MPEA render it a potential material for engineering applications.