Lightweight automotive components based on nanodiamond-reinforced aluminium alloy: A technical and environmental evaluation

This study aims to evaluate the use of nanodiamonds (ND) as potential reinforcements to improve the mechanical properties of aluminium for use in high-quality automotive components. Additionally, the use of components manufactured from reinforced aluminium is assessed regarding environmental effects considering the life cycle of the component. To do this, a master alloy of aluminium/20 vol% ND was developed using mechanical alloying, which embedded and uniformly distributed non-agglomerated ND particles inside the aluminium matrix. Then, specimens of reinforced aluminium alloys containing 0.5 wt% ND were produced using a mixing system to manufacture the final automotive components. SEM images revealed even distributions of nanoparticles of <10 nm in size within the aluminium; synchrotron investigation revealed the diamond structures of the nanoparticles. The incorporation of the nanoparticles induced improvements in the yield stress and ultimate tensile strength, and a dramatic improvement of the ductility. Finally, the holistic life cycle analysis was conducted by the accepted Life Cycle Assessment (LCA) methodology. The results showed an environmental net balance of CO2 emissions after the automobile using ND-reinforced aluminium alloy components had reached ~33% of its useful lifetime, indicating a significant reduction in the environmental impact in the value chain of the component, especially considering 50% recyclability, as this provides environmental benefits compared to the life cycles of equivalent components produced from weightier materials like steel.