Low-Cycle Fatigue Behavior and Fracture Characteristics of Low-Cost Ti-2Fe-0.1B Alloy.

In recent decades, the effect of Fe element addition on titanium alloy has been investigated extensively due to the development of low-cost titanium alloys, as well as B microalloying, which could decrease the grain size of titanium alloys during the casting process. As a key structural material, the study of the fatigue behavior of titanium alloys is crucial and always attractive for scientists. Hence, in this paper, the low cycle fatigue (LCF) behavior and fracture characteristics of a low-cost Ti-2Fe-0.1B alloy with a lamellar structure were investigated systematically, five different strain amplitudes (Δε_t/2) in the range from 0.6% to 1.4% were selected to control the LCF process. It was found that the Ti-2Fe-0.1B alloy exhibits continuous cyclic softening behavior in the cycle as a whole at Δε_t/2 ≤ 1.2%, while at Δε_t/2 = 1.4%, it exhibits slight cyclic hardening at the initial stage of the cycle, then shows cyclic softening. Compared with pure titanium and other typical titanium alloys, the Ti-2Fe-0.1B alloy indicated maximum fatigue life under the same strain amplitude, it can be attributed to the fine grain size result from the effect of Fe element and trace B, which could hinder the dislocation movement and crack propagation. [ABSTRACT FROM AUTHOR]