Determining strain-based fatigue parameters of additively manufactured Ti–6Al–4V: effects of process parameters and loading conditions

This study intends to evaluate the strain-based fatigue parameters of Ti–6Al–4V alloys fabricated through additive manufacturing (AM), considering the effects of AM methods, building direction, and post-processing techniques, including heat treatment and surface finishing. The investigated parameters were fatigue strength coefficients and exponents, as well as the fatigue ductility coefficients and exponents. These parameters are crucial for fatigue life predictions. Fatigue data of different AM specimens were employed to obtain the aforementioned strain-based fatigue parameters under various circumstances. Finally, several case studies dealing with fatigue predictions have been fulfilled using the calculated fatigue parameters to evaluate the accuracy of these parameters. To this end, the effects of notch and loading conditions were assessed through the modified Morrow’s criterion. A reasonable agreement was observed between the available fatigue test data with the predicted results.