Comparing environmental sustainability of additive manufacturing and investment casting: Life cycle assessment of Aluminium LM04 (Al-Si5-Cu3)

Despite manufacturing industries being aware of the potential advantages of adopting Additive Manufacturing (AM), only a few firms have embraced AM-based decision-making processes instead of traditional methods. This study aims to compare the environmental impacts of AM and Investment Casting (IC) using Aluminium LM04 alloy as a case study using the Life Cycle Assessment (LCA) technique under different energy sources, including grid mix (fossil fuel-based energy) and renewable energy sources (wind, solar, biomass, and hydropower). The analysis covers a range of impact categories, (such as Global Warming Potential (GWP), Acidification Potential (AP), Ozone Depletion Potential (ODP), Human Toxicity Potential (HTP), Eutrophication Potential (EP) .... The findings show that AM consistently performs better than IC in reducing environmental impacts, particularly in terms of GWP (19 %), AP (12.5 %), ODP (17.7 %) and ecotoxicity (37.5 %) under the grid mix scenario. When renewable energy sources are integrated, wind energy emerges as the most effective in reducing emissions, of up to 98.3 % in GWP for both processes. IC, while performing better in HTP, still shows higher environmental impacts across key categories compared to AM, especially with grid mix energy. The outcomes demonstrate that the integration of renewable energy significantly enhances the sustainability of both AM and IC. These findings provide key insights for industry stakeholders aiming to adopt sustainable manufacturing practices and contribute to global sustainability efforts. Future work should focus on further optimising IC processes and exploring additional renewable energy scenarios to minimise environmental footprints in manufacturing.