MECHANICAL BEHAVIOUR OF AL-MG-SI MATRIX COMPOSITES REINFORCED WITH ALUMINA AND BAMBOO LEAF ASH

The mechanical behaviour of Al-Mg-Si alloy matrix composites reinforced with alumina and bamboo leaf ash (BLA) has been investigated. Alumina (Al2O3) particulates complemented with 0, 2, 3, and 4 wt% BLA were utilized to prepare 10 wt% of reinforcement in Al-Mg-Si alloy matrix using double stir casting method. Micro-hardness measurement, tensile testing, fracture toughness evaluation, optical and scanning electron microscopy were used to characterize the composites. It was observed that 4.7, 9.32, and 14.3 % reduction in tensile strength was obtained for the composites containing 2, 3, and 4 wt % BLA, respectively. Although there was still a decrease in specific strength and hardness with increase in BLA content, the reductions are less than 9 % for a 40 % reduction of alumina as obtained in the hybrid composite containing 6wt % alumina - 4 wt % BLA. The hybrid composites containing 2 and 3 wt % BLA exhibited a superior elongation in comparison to the single reinforced Al-Mg-Si/10 wt % alumina composite, while all hybrid composite compositions exhibited a superior fracture toughness compared to the single alumina reinforced composite.