A survey on energy efficiency in metal wire deposition processes

Additive manufacturing (AM), which includes different technologies, allows free-form parts to be produced flexibly by selectively depositing material layer after layer. Among the various AM processes, metal wire deposition (MWD), which uses a metal wire melted by a high-energy source as feedstock, has been found to be suitable for the manufacturing of low-complexity,medium-to-large components at relatively high deposition rates. Some industrial applications have been identified, despite the quality of the as-deposited surfaces, which usually require further finishing operations. Several researches have been focused on process optimization. However, there is still a lack of consolidated knowledge concerning the environmental impact and the energy efficiency of MWD, aspects that are critically surveyed in this paper. First, the unit process level is considered, and an analysis of the needed specific energy input, while the wire flow rate and the deposited materials are varied, is carried out. Second, a framework is proposed to assess the energy requirements under a cradle-to-gate perspective