Anisotropy effect of additively manufactured Ti6Al4V titanium alloy on surface quality after milling

The microstructural and mechanical anisotropy of metallic additive manufactured parts is well-established as the nature itself of the process induces the formation of columnar grains along the build-up direction. However, the effect of this anisotropy on the alloy machinability is rarely considered and a deeper understanding is needed. In the current study, Ti6Al4V prisms were fabricated by laser powder bed fusion in both vertical and horizontal orientation. After heat treatment, the prisms were slot milled at different cutting parameters to assess the influence of the build-up orientation on the surface quality, focusing on the surface topography. The results show that the skewness parameter can distinguish the machined surface of differently oriented AM parts and that the horizontal orientation allows for better machinability when considering the burrs height and the chip morphology.