Abstract:The anisotropy of the room temperature (RT) tensile properties, especially plasticity, of Ti-55531 alloy bars was investigated. RT tensile and fracture toughness tests were conducted, as well as OM, SEM, and EBSD characterization. The raw structure, fracture morphology, and crack propagation path were analyzed to reveal the reasons for the anisotropy of the tensile properties of Ti-55531 alloy bars. The results show that due to the <110> texture of the β phase, the Schmid factors for {101}<111> slip systems with different loading directions are different, leading to anisotropy in yield strength; the tensile plasticity is correlated with fracture toughness of Ti-55531 alloy, indicating that the anisotropy of RT plasticity mainly depends on the crack propagation stage and is influenced by the relevant structural characteristics; the anisotropy of RT plasticity Ti-55531 alloy mainly depends on the morphological texture of β grains, and is affected by the orientation texture of β phase and distribution of equiaxed αP.