ETD

• additive manufacturing
• aerospace
• life cycle assessment
• next generation alloys
• supply chain criticality
• sustainability

The rapid expansion of commercial aviation has intensified demand for lightweight, high-performance materials while increasing environmental pressures. Next-generation alloys such as Scalmalloy®, Ti-5553, and ZK60 offer improved strength, corrosion resistance, and design flexibility - especially when combined with advanced methods like Wire Arc Additive Manufacturing (WAAM). However, their environmental sustainability, lifecycle costs, and supply-chain implications remain insufficiently explored.
This project aims to develop an evaluation framework to guide material selection by assessing alloy-route combinations across four key dimensions: mechanical performance, sustainability, cost, and supply-chain criticality. Informed by a systematic literature review, the framework was applied to two case studies: an Airbus A320 main wheel and a Boeing 787 landing-gear forging. The methodology integrates cradle-to-cradle Life Cycle Assessment, cost analysis, mechanical benchmarking, and a novel supply-chain criticality index.
Findings show that although additive manufacturing consumes more energy during production, its lower buy-to-fly ratio reduces total lifecycle energy use and emissions. Since the use phase dominates environmental and cost impacts, lighter materials are generally preferred. Scalmalloy® via WAAM achieved the best overall balance of sustainability and performance, though Ti-5553 emerged as the preferred option when mechanical performance is prioritised in safety-critical applications. These results highlight the importance of integrating mechanical, environmental, economic, and supply-chain factors to enable informed aerospace material choices and provide a practical tool for evaluating trade-offs associated with next-generation alloys.