Corrosion and Tribological Studies of Bamboo Leaf Ash and Alumina Reinforced Al-Mg-Si Alloy Matrix Hybrid Composites in Chloride Medium

The corrosion and wear behaviours of Al matrix hybrid composites prepared using bamboo leaf ash and alumina as reinforcements were investigated in chloride medium. Alumina samples added with 2, 3, and 4 wt% bamboo leaf ash (BLA) were utilized to prepare 10 wt% of the reinforcing phase with Al-Mg-Si alloy as matrix using double stir casting process. Electrochemical studies and wear tests were performed to assess the behaviours of the composites in 3.5% NaCl. The wear and corrosion mechanisms were established with the aid of scanning electron microscopy. The analyses of the results obtained show that the corrosion resistance of the composites decreased with BLA addition in 3.5% NaCl solution. Preferential dissolution of the more anodic Al-Mg-Si alloy matrix around the Al-Mg-Si matrix/BLA/Al2O3 particle interfaces was identified as the primary corrosion mechanism. The coefficient of friction and consequently, the wear rate of the hybrid composite containing 4 wt% BLA was observed to be the highest among the composite samples produced. The single alumina reinforced and the hybrid composites containing 2 and 3 wt% BLA had comparable wear rates with the hybrids showing slightly superior wear resistance.