An economic evaluation of hybrid WAAM-subtractive manufacturing in relation to deposition process parameters

Wire Arc Additive Manufacturing (WAAM) processes could offer significant advantages, in terms of energy and material use efficiency, when used for the production and repair of metal components. However, although a large number of economic assessments have been carried out on powder-based Additive Manufacturing (AM) processes, few studies have addressed the cost of WAAM technologies. There is a lack of research that has simultaneously considered the economic and environmental impacts of hybrid processes based on WAAM. In this study, a cost model, adapted to Cold Metal Transfer (CMT), has been implemented on a steel airfoil mock-up selected as a case study. All the cost drivers have been identified at the different stages of the process, together with their relationships to the deposition process parameters, which have been systematically varied to assess their influence. The results show a close correlation between the overall cost trend and the cumulative energy demand as the process parameters vary, and that the optimisation of the main CMT process parameters should primarily be aimed at increasing the material deposition efficiency, which bridges the CMT and finishing processes.