Energy consumption assessment in manufacturing Ti6Al4V electron beam melted parts post-processed by machining

The assessment of energy consumed in manufacturing operations and the enhancement of their sustainability plays a fundamental role in the present research contest. Electron beam melting (EBM) is an additive manufacturing technique that allows the fabrication of titanium parts with high productivity and a low buy-to-fly ratio; on the other hand, the roughness of the parts is not adequate for high-performance applications, so a finishing step is always required. Aiming to reduce the energy used to produce a part, all the required manufacturing steps should by carefully treated in an integrated framework. The aim of this paper is to study the energy required to produce a Ti6Al4V part printed through EBM and the machined to achieve the desired surface finishing. Cylindrical specimens have been printed through an Arcam machine by using the processing conditions suggested by the manufacturer; then, the specimens have been turned under different processing conditions. The energy required in all the phases has been recorded and then carefully analyzed to point out the processing conditions which allows a more efficient use of resources. The results showed that the printing phase is by far the most energy demanding so should be carefully treated to reduce the printing time even if a greater roughness is achieved; the analysis of the machining stage suggested that both depth of cut and spindle speed must be kept the higher as possible to reduce the energy consumption of this stage.