Abstract:The low-cycle dwell fatigue behavior and fracture characteristics of a cost-effective Ti-2Fe-0.1B alloy with lamellar microstructure were investigated. Strain-controlled low-cycle fatigue tests incorporating tension-compression with dwell time of 0, 2, and 10 s were conducted under various strain amplitudes. The results reveal that at lower strain amplitudes (Δεt/2=0.6%), specimens with all dwell durations exhibit continuous cyclic softening during initial cycles. Conversely, at higher strain amplitudes (Δεt/2=1.4%), an initial cyclic hardening phase precedes subsequent softening, which is primarily attributed to dislocation multiplication and entanglement, forming temporary barriers that impede plastic deformation in early stages. The fatigue life of Ti-2Fe-0.1B alloy demonstrates significant strain amplitude and dwell time dependence. At high strain amplitude (Δεt/2=1.4%), the life reduces (710→426 times). At intermediate strain amplitude (Δεt/2=1.0%), specimens maintain stable fatigue life under short dwell periods (1604→1610 times), while low strain amplitude (Δεt/2=0.6%) testing reveals non-monotonic life variations (15 478→8543→8887 times) with the prolongation of dwell time. Comparative analysis with conventional titanium alloys (TA15, Ti80) demonstrates that dwell fatigue resistance of Ti-2Fe-0.1B alloy is better. Microstructural characterization of fracture profiles reveals the presence of precipitated TiB phases. These high-strength and high-hardness precipitates contribute to enhanced matrix strength and can provide effective crack propagation resistance through reinforcement mechanisms, which improves the overall fatigue performance of alloy's.