Solid-State Additive Manufacturing: An Innovative Framework for Sustainable Supply Chain Transformation and Circular Economy

As recent regional conflicts and the Covid pandemic have shown, global supply chain disruptions can destabilize even the most developed economies. Added to this is the ever-growing need for comprehensive closed-loop, multi-life cycle based sustainable manufacturing practices, which encompass the entire supply chain across the product, process, and system levels. Additive manufacturing (AM) technologies in recent times have unlocked powerful new tools which offer potential solutions for these challenges, allowing for enhanced supply chain resilience and flexibility, while providing new pathways for increased product and process sustainability. However, metallurgical bonding and layer building in conventional fusion-based AM technologies rely upon high powered energy sources, which significantly increase the ecological impact of these processes. Solid-state additive manufacturing is an emerging AM modality in which deposition occurs at elevated temperatures below the material's melting point, allowing for reduced energy environmentally friendly processing routes. Solid-State additive friction stir deposition (AFSD) is unique in its ability to facilitate multiple life cycles through leveraging of manufacturing waste directly as feedstock, thus giving new life to material that would otherwise be recycled or discarded as waste. This paper will introduce AFSD through the prism of upcycled aluminium waste, examine its supply chain influence using a standardized framework, and assess the sustainability and circular economy benefits of AFSD in comparison to conventional fusion-based AM and traditional recycling technologies. This analysis reveals that utilization of AFSD can substantially transform existing supply chains, especially in the domain of large-scale rapid component manufacturing, while providing increased sustainability at all levels of the supply chain.