Surface finish of additively manufactured Ti6Al4V workpieces after ball end milling

This work investigates the machinability characteristics of additively manufactured Ti6Al4V titanium alloy workpieces in finishing machining using ball end mills on 45° inclined surfaces. The surface finish results were compared with the ones from ball end milling trials on wrought Ti6Al4V samples using the same cutting conditions. Optical profilometry and scanning electron microscope imaging were used to compare the different surface texture and quality of the two alloys, as well as the chip morphology, with the aim of finding a correlation between the surface finish obtained at varying cutting parameters and the Ti6Al4V peculiar microstructure induced by the additive manufacturing process. The results showed that the additively manufactured alloy allowed for a better surface quality respect to the wrought one. This was attributed to the interactions of the ball mill cutting edge with the α phase colonies of such alloy, which may favor the material removal by locally lowering the material resistance to cutting.