Fatigue prediction and life assessment method for metal laser powder bed fusion parts

In this paper, an industry-accepted fatigue model based on generalized stress-life (S–N) curves is adapted for metal parts fabricated by laser powder bed fusion (LPBF). Initial defects inherent to the fabrication process, such as part porosity, are related to fatigue life performance. Hereto, additively manufactured test specimens are fatigue tested and used to formulate a function to predict fatigue life based on the size of initial defects. The predictions correlate well with experimental results and provide a quality measure to expel outliers. The method can be used to predict the life expectancy of LPBF parts based on a priori detected defect sizes.