Focusing on large TC18 titanium alloy bars with a diameter of 400 mm, the tensile properties, microstructural characteristics, fracture morphology, and characteristics of voids in the fracture surface profile were systematically investigated at four locations: the center transverse (CT), center longitudinal (CL), edge transverse (ET), and edge

longitudinal (EL) locations. The tensile results demonstrate that edge samples exhibit a significant strength advantage, with the ET sample achieving a tensile strength of 1 230 MPa. The longitudinal sample exhibits superior plasticity, with the CL sample exhibiting the highest elongation of 16.5%. Compared with the core samples, the longitudinal samples contained 5% more equiaxed αp phase, whereas the edge samples present smaller dimensions of the lamellar secondary αs phase. Fractography reveals typical ductile fracture characteristics with uniformly distributed dimples. Further characterization of tensile fracture cross-sections reveals three types of void formation: within αp,at the αp-β interface, and within the β phase.