Fatigue crack growth behavior of a selective laser melted AlSi10Mg

Selective Laser Melting is an additive manufacturing technology capable of producing relatively dense parts from metallic and alloy powders using a high-power laser beam. The present study examines the high cycle fatigue crack growth behavior in the linear region of da/dN vs. Delta K diagrams of the AlSi10Mg alloy produced by SLM. Specimen building orientation and notch position have been combined to obtain 4 different crack growth orientations. Further, specimens were tested in both as-built (AB) and T6 heat treated (T6) conditions. The Fatigue Crack Growth (FCG) curves revealed the beneficial influence of the heat treatment on the FCG response, as compared to the as-built case. On the other hand, the fatigue crack growth behavior of the latter is found to be strongly dependent on material orientation. Fractographic analysis have been further performed to understand the mechanisms involved. Additionally, residual stress measurements were also performed to comprehend its contribution on the FCG curves.