Integrated WAAM-Subtractive Versus Pure Subtractive Manufacturing Approaches: An Energy Efficiency Comparison

Over the last years, additive manufacturing (AM) has been gathering momentum both in the academic and in the industrial world. Besides the obvious benefits in terms of flexibility and process capabilities, the environmental performance of such processes has still to be properly analyzed. Actually, the advantages of additive manufacturing over conventional processes are not obvious. Indeed, different manufacturing approaches result in different amounts of involved material and in different processing energy demands. Environmental comparative analyses are hence crucial to properly characterize AM processes. In this paper, an energetic comparison between the emerging wire arc additive manufacturing (WAAM) process and a traditional machining-from-bulk solution to produce a steel blade is presented. A methodology accounting for all the material and energy flows of the whole component life cycle is proposed. Experimental measurements and environmental databases are used to quantify the primary energy demand at each stage of the life cycle. The results reveal that, for the analyzed case study, an integrated additive (WAAM)-subtractive manufacturing route enables significant material and primary energy savings with respect to traditionally applied approaches.