▎ 摘　　要

This study focuses on understanding the corrosion and tribological behaviour of hybrid aluminium composites in diverse environmental conditions (dry, aqueous and alkaline). The characteristics are compared under corrosive conditions to check the tendency to wear and corrosion for its probable use in marine applications. Eutectic aluminium-silicon (Al-Si) alloys and hybrid aluminium composites enhanced with alumina (6 wt%) and varying weights of graphene nanoplatelets (GNP) (1, 2, 3 wt%) samples were fabricated by spark plasma sintering. The corrosion behaviour of the hybrid composites was investigated by potentiodynamic polarization technique using 3.5 wt% NaCl solution as electrolyte. A chromium-plated chrome steel ball of 10-mm diameter was used for the ball-on-disk test at varying load (50-250 N), sliding velocity 0.12 m/s, sliding distance 120 m, frequency 30 Hz, stroke 2 mm, and test duration 1000 s to evaluate the tribological behaviour. An increase in the corrosion and tribological performance was observed with an increase in GNP concentration in the fabricated hybrid composite sample. Composite sample with 3 wt% of GNP had the highest average electrochemical open-circuit potential value of - 0.731 V, followed by 2 wt% (- 0.743 V), 1 wt% (- 0.747 V) and base (- 0.771 V). The presence of GNP reduced the vulnerability to corrosive degradation as being superhydrophobic, it inhibited the chloride ion attack by offering lesser adsorption of the salt solution on the hybrid composites' surfaces. The wear mechanism was discussed by interpretation from scanning electron microscopy, energy dispersive X-ray analysis (EDX) and 3D surface profilometry. The formation of carbon protective layer at the interface led to a reduction in coefficient of friction and wear of hybrid composite with 3 wt% of GNP by more than 90% and 60%, respectively, at all environmental conditions as compared to base alloy.