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.