β-titanium alloys like the alloy Ti-5Al-5V-5Mo-3Cr show a high performance-to-density ratio, good corrosion resistance and good fatigue properties. Therefore, these alloys are attractive materials for aerospace and biomedical applications. Advances in additive technologies are leading to an increase in additively manufactured parts, offering new opportunities for functional integration and lightweight structures. Although additively manufactured parts are near-net-shape, most of them are machined after the build process to fulfil surface finish and dimensional accuracy requirements. Titanium is generally known as a difficult to machine material due to its thermomechanical properties. Although there is a substantial knowledge on the machinability of conventionally cast and wrought titanium alloys, there is a lack of knowledge on the machining of additively manufactured titanium.

Subject of this work is the analysis of the machinability of additively manufactured Ti-5553 in terms of chip formation, cutting forces and tool wear. Different parameter sets of the laser powder bed fusion (LPBF) process are used to produce samples with different microstructures and mechanical properties. Additionally some of these samples are heat treatet with different industrial heat treatments. Subsequently, the machinability is investigated in comparison to a conventional wrought and heat treatet sample. The machinability differs significantly depending on the process parameters of the LPBF process. The highest tool load for the samples without heat treatment is found for a titanium alloy produced with the highest energy density of the LPBF-process. The higher tool wear in these samples is probably due to the precipitation of α-phase as a result of the high energy input and the associated ageing effects. In summary, it can be demonstrated that the process parameters of the LPBF-Process have a significant influence on the machinability.