Surface roughness effect of SLM and EBM Ti-6Al-4V on multiaxial high cycle fatigue

•Surface roughness drastically reduce fatigue strength.•High resolution 3D surface measurements allow to model near surface stress field.•Stress gradients induced by surface micro-notches are of hundreds MPa/micron.•A non local fatigue indicator parameter is needed capture gradient effects.•The proposed statistical methodology is able to predict tension and torsion fatigue tests of as built SLM specimens.