The influence of microstructure on mechanical properties of SLM 3D printed Ti-6Al-4V

This research focuses on establishing the relationship between the SLM process parameters, microstructure and mechanical properties in 3D printed ti-6Al-4V. To this end modelling of the thermal history, reflecting the applied process parameters, is linked to the as-printed microstructure, which, in turn, is linked to experimentally determined mechanical properties. The very high cooling rates in the centre of the specimen, as predicted by modelling, lead to a fine, martensitic microstructure, while the slower cooling rates close to the support structure lead to a fine lamellar α+β microstructure. The tensile properties, in particular the ductility, were found to depend on the printing orientation and surface finish.