Microstructural, mechanical and energy demand characterization of alternative WAAM techniques for Al-alloy parts production

Additive manufacturing (AM) processes are gathering momentum as an alternative to conventional manufacturing processes. A research effort is being made worldwide to identify the most promising AM approaches. Within this category, wire arc additive manufacturing (WAAM) is among the most interesting, especially when large parts must be manufactured. In this paper, two different WAAM deposition techniques suitable for the deposition of Aluminum alloys, Cold Metal Transfer (CMT) and CMT mix drive, are analyzed and compared. With the aim of obtaining a clear picture concerning the two different techniques, microstructural analyses, mechanical property evaluation and electrical energy demand characterizations were conducted. The results revealed that both techniques allowed sound components to be manufactured and no significant differences were observed in terms of their microstructural and mechanical properties, while CMT was also found to provide a relevant energy saving. This allows the selection of the best technology taking into account not only the geometrical characteristic of the part but also the environmental impact associated to each technique