A modelling framework for fatigue-life prediction of selective laser melting additive manufactured Ti-6Al-4V

Abstract

Selective laser melting (SLM) enables the fabrication of complex, lightweight structural parts that would be impossible to be produced with conventional methods. Despite its advantages SLM process has some intrinsic drawbacks, with the formation of defects in parts being one of the most serious, as defects detrimentally affect the fatigue behavior of SLM parts. In order to consider defects in SLM part design and production, reliable models for defect-based fatigue life estimation models should be developed. The current work presents a modelling framework for the prediction of susceptible areas for defect formation and subsequently fatigue life estimation of SLM components. The ability of this modelling framework to effectively predict the fatigue life was tested on the prediction of fatigue life of SLM Ti-6Al-4V specimens. The small fatigue crack growth behavior of AM Ti-6Al-4V was considered. The prediction results of a fatigue life model were successfully compared with experimental data verifying the current modelling approach. Limitations concerning the prediction results are attributed mainly to the assumptions performed and the considered defect size which will be thoroughly investigated in future works.