Environmental and economic assessment of a steel wall fabricated by wire-based directed energy deposition

Abstract

Over the past few decades, adoption of different Additive Manufacturing (AM) processes has gained momentum in the manufacturing industry. One such emerging AM process is wire-based directed energy deposition. Environmental impacts and costs are important criteria for adoption of any manufacturing process. Therefore, the aim of this paper is to evaluate the environmental and economic performance of Wire and Arc Additive Manufacturing (WAAM) using Life Cycle assessment (LCA) and Life Cycle Costing (LCC) methodologies. In this paper, an integrated methodology to conduct a cradle-to-gate LCA based on the guidelines of ISO 14044 and LCC based on IEC 60300–3–3 standards is proposed. A case study of a single steel wall manufactured by WAAM was analysed. The environmental impacts and production costs for wire-based directed energy deposition process were compared to laser powder bed fusion (LPBF) and Computer Numeric Control (CNC) milling processes. For the steel wall analysed, CNC milling was the most economical and ecological option followed by the wire-based directed energy deposition and LPBF. However, the performance of a process depends on product complexity and the manufacturing process's material efficiency. Raw material production and labour were identified as major environmental hotspot and cost driver, respectively, in wire-based directed energy deposition. The methodology used in this paper can be extended to other manufacturing processes.