Comparative environmental impact assessment of additive-subtractive manufacturing processes for Inconel 625: A life cycle analysis

Abstract

This paper presents a life cycle assessment (LCA) approach to compare the environmental impacts of additive-subtractive manufacturing processes for Inconel 625. The LCA follows a cradle-to-gate methodology and employs the Eco-chain Mobius Software, in accordance with ISO 14044 standards. The chosen LCA model enables industries to develop sustainable production techniques by evaluating 18 environmental variables' potential effects on human health, ecosystems, and resource availability. The LCA adopts the midpoint(H) approach from ReCiPe 2016 to comprehensively assess the environmental impacts. In the first case study, a plate is created using the Wire Arc Additive Manufacturing (WAAM) method, followed by post-processing through drilling in both wet and dry environments. The dry condition results in a remarkable 24.23% reduction in environmental impact when the LCA is applied to the entire process, making it the most sustainable choice. In the second case study, a hollow cylinder is manufactured using the WAAM technique, and post-processing is conducted using turning processes under cryogenic, dry, and electrostatic minimum quantity lubrication (EMQL) conditions. The dry environment yields a 16.4% lower impact on the environment, establishing it as the most sustainable choice. Overall, the results from both case studies demonstrate that utilizing WAAM technology in a dry environment leads to the most sustainable manufacturing procedure for Inconel 625. This comparative analysis provides valuable insights to support the development of environmentally friendly production techniques in the manufacturing industry.