MECHANICAL AND CORROSION BEHAVIOR OF ARTIFICALLY AGED ALUMINUM COMPOSITE DERIVED FROM LOCALLY SOURCED MATERIAL

This study investigates the mechanical and corrosion behavior of artificially aged aluminum alloy 6061reinforced with metakaolin derived from locally sourced kaolin. Composites containing 2 wt.%, 4 wt.%, and 6 wt.% metakaolin were produced using stir casting technique and subjected to solution treatment, quenching, and artificial aging at 150 °C, 200 °C, and 250 °C. Mechanical properties were evaluated through hardness, impact, wear, and tensile testing, while corrosion resistance was assessed via potentiodynamic polarization in 3.5 wt.% NaCl solution. Results showed that reinforcement and aging temperature significantly influenced performance. The 2% metakaolin composite aged at 150 °C recorded the highest hardness (66.48 BHN), while the 2% sample at 200 °C achieved the best impact resistance (32.64 J). Wear resistance exhibited mixed trends: the 6% reinforcement at 150 °C reduced wear by over 50% compared to the control, but coarse particle size (212 µm) often led to agglomeration and increased abrasive wear. Corrosion resistance improved markedly at moderate reinforcement and higher aging temperatures, with the 4% composite aged at 250 °C showing the lowest corrosion rate (4.52 mpy), an 81% reduction compared to the control. Overall, the findings confirm that locally sourced metakaolin can enhance mechanical and corrosion performance of AA6061 when optimized, providing a cost-effective and sustainable reinforcement option. The balance between reinforcement content, particle size, and heat treatment is critical for achieving desirable properties