Evaluation on the fatigue behavior of sand-blasted AlSi10Mg obtained by DMLS

Fatigue tests were performed on sand-blasted AlSi10NIg samples produced by Direct Metal Laser Sintering (DMLS) of powders. The effect of sand-basting on surface properties was evaluated by roughness and residual stresses measurements, together with morphological analysis, in comparison with as fabricated condition. An evident improvement of surface finishing was observed after sand-blasting, which also lead to the presence of compressive residual stress on the external surface of samples, as revealed by XRD measurements. Furthermore, defects analysis allowed the identification of a uniform distribution of porosities in the cross section whereas larger porosities seem more abundant close to the surface. It was found that the tested material exhibits good fatigue resistance, supporting the positive role of sand-blasting as a simple post-processing treatment. Superficial defects are the preferential crack initiation sites, as demonstrated by SEM analysis of fracture surfaces.