Fatigue Behavior and Life Prediction of Additively Manufactured AlSi10Mg up to 108 Cycles Under Rotating Bending

Laser powder bed fusion (L-PBF) technology has been commonly used in various industries to manufacture small-lot or complex parts. However, process-induced defects are inevitable, which limits the adoption of L-PBF alloys for load-bearing components. This work studied the fatigue behavior of L-PBF AlSi10Mg subjected to rotating bending loading up to 10⁸ cycles, and compared two batches of specimens with different layer thicknesses of 50 and 80 μm. The results indicate that the specimens with a layer thickness of 50 μm exhibit better fatigue strength compared to those with a layer thickness of 80 μm. Fracture analysis shows that lack of fusion defects are the crack initiation location, and the characteristics of these defects have a significant effect on the fatigue behavior. Furthermore, the Kitagawa–Takahashi diagram was used to determine the safe life region in terms of the El-Haddad formula. Finally, by taking into account the size, location, and shape of the defects, a modified model was proposed to predict the fatigue life. The predicted results are in good agreement with the experimental results.