Development of Fatigue Damages in a Pseudo-α-Titanium Alloy after Intense Thermomechanical Treatment

Resumo

The influence of surface hardening by electrochemical treatment, abrasive-free ultrasonic finishing treatment, and their combination on the accumulation of fatigue damages in a pseudo-α-titanium alloy (PT3V) during pulsed cyclic loading in a transition stage of fatigue (10⁴–10⁵ cycles) is studied. The fatigue damage accumulation kinetics is estimated using the inelasticity parameters of a specimen (hysteresis loop width, cyclic creep, rigidity (compliance)) during cyclic loading, an analysis of fracture surfaces, and the crack growth rate. The state of surface layer is shown to play a key role in the change in the fatigue life of laboratory specimens. The type of surface hardening only weakly affects the accumulation of fatigue damages at the stages of stable crack growth and rupture.