Development and evaluation of a recycled aluminum alloy for sustainable automotive applications

Thesis Abstract

The increasing demand for sustainable and lightweight materials in the automotive industry necessitates the exploration of recycled aluminum alloys as viable alternatives to virgin materials, addressing both environmental concerns and resource conservation. This study aims to develop and evaluate a recycled aluminum alloy with enhanced mechanical and thermal properties suitable for automotive applications, thereby contributing to sustainable manufacturing practices. The research specifically seeks to optimize alloy compositions through a systematic blend of primary scrap materials and post-consumer aluminum waste, ensuring both economic viability and environmental compliance. A mixed-methods approach was employed, involving experimental material synthesis coupled with analytical and statistical evaluation. The experimental phase involved melting, casting, and thermo-mechanical processing of aluminum scraps to produce several alloy variants, with sample sizes of 50 specimens per alloy composition to allow for statistically robust analysis. The population comprised post-consumer aluminum waste collected from scrap yards and automotive recycling facilities, ensuring diversity in the raw materials. Data collection instruments included X-ray fluorescence spectroscopy (XRF) for compositional analysis, scanning electron microscopy (SEM) for microstructural characterization, and mechanical testing protocols such as tensile, hardness, and fatigue tests following ASTM standards. Additionally, thermal analysis through differential scanning calorimetry (DSC) and thermal conductivity tests were carried out to evaluate heat transfer properties relevant to automotive uses. Quantitative data were analyzed primarily through analysis of variance (ANOVA) to assess differences in mechanical and thermal properties across alloy variants, while regression analysis was employed to model the relationship between alloy composition and performance metrics. Microstructural features were interpreted with the aid of SEM images, and findings were integrated with mechanical test results to identify optimal alloy formulations. The study also applies the theory of materials recycling and resource efficiency to frame the environmental benefits of the developed alloys. Preliminary results are expected to reveal that specific alloy compositions, notably those incorporating controlled additions of silicon and magnesium, exhibit enhanced tensile strength, ductility, and thermal stability without compromising recyclability. It is anticipated that the optimized alloy will demonstrate at least a 15% improvement in yield strength and a 10% increase in thermal conductivity compared to conventional recycled aluminum alloys, meeting or exceeding industry standards for automotive components. These findings are projected to suggest that carefully formulated recycled alloys can offer a sustainable and economically feasible alternative to primary aluminum, with significant environmental benefits by reducing energy consumption and landfill waste. This research significantly contributes to existing knowledge by providing empirical evidence and a comprehensive framework for developing high-performance recycled aluminum alloys tailored to automotive applications. It advances the understanding of how alloying elements influence microstructure-property relationships in recycled materials and informs best practices for industrial recycling processes. The study's conclusions underscore the potential for integrating such alloys into manufacturing pipelines, supporting sustainability initiatives in the automotive sector. Based on the findings, recommendations include further scaling of the alloy production process, exploration of additional alloying strategies for enhanced performance, and assessment of long-term durability under operational conditions. The study advocates for policy and industry adoption of recycled aluminum alloys to promote circular economy principles within automotive manufacturing. Future research should explore the life cycle assessment of the developed alloys and investigate their performance in real-world structural applications to validate laboratory findings and facilitate commercial deployment.