Unit process energy consumption analysis and models for Electron Beam Melting (EBM): Effects of process and part designs

Electron Beam Melting (EBM) has the potentiality of being an effective system in terms of time and energy consumption. Among the different additive manufacturing processes that are available, the EBM process has shown the lowest Specific Energy Consumption (SEC) and the highest average Deposition Rate (DRa). However, there appears to be a lack of literature on the correlation between SEC and DRa. Moreover, all the literature studies have only an analysis of energy efficiency during the melting of the bulk material phase and have adopted a fixed job design. Therefore, the aim of this study has been to fill this gap. The EBM process is decomposed into small substeps and a bottom-up approach is adopted to provide models that can be used to evaluate the energy of each process subphase and to perform an energy characterisation at the unit process level. A black-box approach is applied to provide a new model for the energy efficiency of the EBM process. Different jobs have been designed to analyse the effect of a part and of manufacturing designs. Bulk material, support and lattice structures have been included. The design has therefore been aimed at investigating the effect of the building height, melted area and process themes on energy efficiency. The jobs have been produced using Arcam A2X and Standard Arcam Ti6Al4V powders. According to this research, the architecture of the machine and its control of the process have the main impact on the relationship between SEC and DRa. The design features of the part and of the job influence the position of the job on this curve and thus the relative energy and time efficiency. Additionally, the empirical approach applied to the machine subunits has highlighted that only a small part of the total energy demand is needed to power the electron beam during the melting phase, while the remaining part guarantees the good machine working conditions.