Effect of Processing Route on the Mechanical and Tribological Behaviour of AA8011 Hybrid Composites

In this work, the effect of processing route on physical and tribological properties of cast AA8011 alloy, squeeze cast AA8011 alloy and stir cum squeeze cast AA8011 with 5wt% ZrO 2 & 5wt% Al 2 O 3 composite were investigated. Squeeze cast AA8011 alloy shows pore free fine structure when compared to as cast AA8011 alloy. In hybrid composite, ZrO 2 and Al2O 3 particles are homogeneously distributed with the matrix due to squeezing effect. Hardness of the hybrid composite is 45% higher than squeezed and base alloy. Pin-on-disc Tribometer is used to study the wear properties of castings produced. Wear rate of the hybrid composite is 60% lower than the as cast AA8011 alloy. Coefficient of friction is also low in hybrid composite compared to other alloys. This is owing to the AA8011 matrix's uniform distribution of reinforcement particles closely bonded with matrix due to applied load acting on the liquid melt. Abrasion and adhesive mode of wear mechanisms were observed in the casted specimens.