Toward Sustainable Supply Chains in Metal Additive Manufacturing: An Energy-Based Limited-Scope Global Warming Potential (GWP) Life Cycle Assessment of Oxygen-Free High Conductivity Copper Powder Production

Powder metallurgy processes manufacture products from metal powders, which can be produced using various methods. When customer requirements permit, powder metal processes can produce products in an additive rather than a subtractive fashion. Thus, this approach reduces the waste associated with traditional subtractive metallurgical forming processes such as machining. In addition to lowering material waste, enhancing design flexibility, and improving process efficiency, additive manufacturing of powder metallurgy products can also reduce environmental impact by reducing energy consumption, raw material use, emissions, transportation, and waste generation. Furthermore, the use of alternative methods for manufacturing metal powders can further reduce environmental impact. In this study, an energy-based limited-scope global warming potential life cycle assessment is presented that compares the carbon intensities of manufacturing critical products made of oxygen-free high-conductivity copper powder via two different powder production routes: electrode induction melting gas atomization, and the DirectPowderTM System, within additive manufacturing supply chains. Instead of relying on single-point estimates, this study uses a Monte Carlo simulation to account for uncertainty and variation in input data. Results indicated that the DirectPowderTM manufacturing pathway had a 39.4% lower global warming potential per kg of usable powder when parts were manufactured via laser powder bed fusion. When only the powder manufacturing methods were included in the analysis, the DirectPowderTM method demonstrated the potential to reduce global warming impact by 92.9% when compared to the electrode induction melting gas atomization process. In total, 11.44 kg CO2-eq per kg of OFHC copper produced is saved when using the DirectPowderTM process. This research provides new insights into the tradeoffs between the environmental impact and functional capabilities of these methods. It offers valuable guidance on process selection for product designers and supply chain professionals seeking to optimize product performance, energy use, and environmental footprint.