This thesis investigates the influence of accumulative 'tramp elements' — unintended impurities such as Fe — in aluminium alloys, specfically their detrimental impact on material properties and processability. Understanding and mitigating the effects of tramp elements is critical to improving the quality and lifecycle of recycled aluminium. This research aims to develop strategies for compensating for the adverse impacts of these elements, thereby enhancing the sustainability of aluminium. The study employs a range of material models, with a particular focus on through-process modelling, to examine the mechanisms by which tramp elements affect aluminium alloys. It aims to refine existing models and develop novel processing strategies to mitigate the effects of tramp elements. In the initial sections, the thesis outlines the metallurgy of aluminium alloys, the landscape of aluminium recycling, and the specific impacts of tramp elements. It further details the material models applied across various production stages. From here, two research pathways are identified: the first focuses on further understanding the effects of intermetallics on formability, and the second on using through-process models to compensate for the effects of tramp elements.

Chapter 3 explores the use of crystal plasticity modelling to examine the impact of intermetallic distributions and volume fractions, increased by tramp element content, on the formability of aluminium as part of the EPSRC Lightform project. A modelling pipeline was developed to generate representative models for the DAMASK framework from experimental data. From this point, the study evaluates strain localisation as a metric for formability, using several techniques applied to `toy' models. The findings suggest that the efficacy of strain localisation using these techniques to predict formability is limited, prompting further investigation into alternative metrics.

Subsequent chapters shift the focus to the hot forming of 6xxx series aluminium alloys. Chapter 4 details lab-scale experiments on 6082.50 and two 6110 alloy variants, including finite element modelling and constitutive data generation. This approach demonstrated robust fits of the finite element model to the thermal fields and stress-strain responses in the experiments. However, when constitutive data generated by the PRO3™ through-process modelling platform is used, discrepancies arise in the predictions of stress-strain behaviour compared to experimental outcomes. Additional discrepancies are observed in recrystallisation behaviour, as explored in Chapter 5, although a reasonable fit to ageing behaviour is observed. These discrepancies, attributed to limitations in the modelling capabilities, highlight the need for further development and refinement of these models. In the final chapter, Chapter 6, the models are utilised to demonstrate two case studies of process compensation. Adjustments in homogenisation and hot deformation parameters are used to effectively counterbalance the effects of increased tramp elements. Although these test cases demonstrate effectiveness in simple scenarios, it is concluded that for the broader application of process compensation, the models require further refinement.