Corrosion and Wear Behaviours of Aluminium Composites Reinforced with Palm Kernel Shell Ash and Silicon Carbide

Corrosion and wear properties of hybrid aluminium matrix composites (HAMCs) reinforced with palm kernel shell ash and silicon carbide were studied. Composites with 6, 8, 10 and 12 wt% reinforcements and varied mix ratios were produced using double-step stir casting method. Corrosion in 0.3 M H₂SO₄ and 3.5% NaCl media were investigated using potentiodynamic polarization method, while the wear behaviour was evaluated using multifunction tribometer. The unreinforced aluminium (Al) alloy showed higher corrosion rates (1.2323 and 0.020167 mmpy for 0.3 M H₂SO₄ and 3.5% NaCl media, respectively) than most of the composites in both media. However, corrosion trends were invariant to reinforcement weight per cent and mix ratio. For wear behaviour, average COF were higher for most of the composites (within the ranges of 0.57–0.70 for 10 N load and 0.54–0.70 for 20 N) than unreinforced Al alloy (0.54 and 0.51 for 10 N and 20 N loads, respectively). Wear mechanism of the HAMCs was established to be predominantly abrasive and adhesive wear, facilitated by plastic shearing which resulted in extensive grooving and adhesion of wear debris on the substrate.