The automotive industry needs more lightweight materials, prompting the focuson optimising aluminium alloys to achieve the highest mechanical performance.This project investigates the assumption that variations in location andthickness within a component leads to different mechanical properties. Anunderstanding of varying mechanical properties and their correlation withmicrostructure is essential for optimising these alloys.The research utilised tensile testing and Digital Image Correlation (DIC)methods to observe strain concentrations, aiming at defect identification.The analysis of the fracture surface was performed using Scanning ElectronMicroscopy (SEM), which revealed hidden damages such as oxides, bi-films, andporosity shrinkage. Energy Dispersive Spectroscopy (EDS) was employed toidentify the elemental composition of fracture surfaces. The study alsoexplored the correlation between Secondary Dendrite Arm Spacing (SDAS) andmechanical performance, with measurements of SDAS compared with the tensiletest results. Image analysis quantified average porosity percentages aroundthe component, which were then compared to casting simulation results. In-situ tensile testing, performed using SEM, allowed for the observation ofcrack propagation in various locations and thicknesses.Statistical analysis indicated that variations in thickness and location didnot result in significantly different mechanical characteristics within thecomponent. The exception was observed in the pillars of the sample, whichhad the greatest thickness and cylindrical shape, that exhibited poorermechanical performance. Thicker samples showed increased porosity and oxideformation, which correlates with lower solidification rates and higher SDAS,thereby weakening the material. DIC analysis supported these observations,identifying high strain concentrations linked to hidden defects in the melt.In-situ tensile testing further corroborated these findings with the presenceof oxides, showing more frequent crack propagation in thicker samples.The study highlights the critical impact of sample thickness and coolingrates on the mechanical properties of aluminium alloys, revealing areas forpotential optimisation in high-performance applications.