The Influence of Layer Thickness on the Fatigue Life of Laser Powder Bed Fusion Manufactured AlSi10Mg Parts

The effect of production efficiency to the material properties of laser powder bed fusion (PBF-LB) manufactured AlSilOMg parts was investigated in this work. Production time can be reduced by increasing the used layer thickness, but the trade-off is typically reduced material quality. AlSilOMg parts were manufactured with three different layer thicknesses, 30, 60 and 90 µm to study the influence on microstructure, mechanical properties and fatigue strength of the material. The results show that most of the material properties are affected by the increased build speed. The microstructural changes and added porosity lower the strength of the material but also have a major impact on the fatigue life of the material. It was shown that the vertical direction is the most prone to critical defects that lower especially the fatigue strength in bending loading. Interesting finding was that the fatigue strength in horizontal direction was not affected by the layer thickness.