Proposing a material selection indicator for the design of extended lifespan products.

Material durability has emerged as a key factor influencing product longevity, safety, and cost-effectiveness across various sectors, including the construction, automotive, and electronics sectors. With the growing emphasis on sustainability, there is an increasing demand for materials that not only exhibit high performance but also align with circular economy practices such as reuse, repair, remanufacturing, and repurpose. The challenge lies in the existing material selection frameworks, which frequently fail to comprehensively integrate multiple aspects of durability with environmental impact. Most current indicators predominantly focus on ensuring material durability over time without sufficiently considering the complete lifecycle environmental footprint. To address these challenges, this study introduces the Specific Durability Performance, a quantitative approach that merges mechanical, thermal, and chemical durability with a carbon footprint into a singular value ranging from 0.0 to 1.0. The methodology involves calculating key parameters for each material, such as tensile strength, fatigue resistance, service temperature range, flammability, and chemical resistance, which are weighted according to the criteria that assess the specific use requirements of the product. Each dimension of durability was benchmarked against an "ideal" reference material, and the carbon footprint was also benchmarked. These results were then synthesized into a unique score designed to facilitate material selection by balancing performance and sustainability. This approach was applied to two case studies with distinct design requirements, demonstrating the usefulness of the proposed indicator in identifying materials that offer robust structural performance and reduced environmental impact.